/*
 * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#include "config.h"

#if ENABLE(VIDEO)
#include "HTMLMediaElement.h"
#include "ApplicationCacheHost.h"
#include "ApplicationCacheResource.h"
#include "Attribute.h"
#include "Chrome.h"
#include "ChromeClient.h"
#include "CDMInstance.h"
#include "ClientRect.h"
#include "ClientRectList.h"
#include "ContentSecurityPolicy.h"
#include "ContentType.h"
#include "CSSPropertyNames.h"
#include "CSSValueKeywords.h"
#include "DiagnosticLoggingKeys.h"
#include "DOMWrapperWorld.h"
#include "DocumentLoader.h"
#include "ElementChildIterator.h"
#include "Event.h"
#include "EventNames.h"
#include "ExceptionCode.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameLoaderClient.h"
#include "FrameView.h"
#include "HTMLDocument.h"
#include "HTMLNames.h"
#include "HTMLSourceElement.h"
#include "HTMLVideoElement.h"
#include "Language.h"
#include "Logging.h"
#include "MediaController.h"
#include "MediaControls.h"
#include "MediaDocument.h"
#include "MediaEncryptedEvent.h"
#include "MediaError.h"
#include "MediaFragmentURIParser.h"
#include "WebKitMediaKeyError.h"
#include "MediaKeyEvent.h"
#include "MediaKeys.h"
#include "MediaList.h"
#include "MediaPlayer.h"
#include "MediaQueryEvaluator.h"
#include "MouseEvent.h"
#include "MIMETypeRegistry.h"
#include "NotImplemented.h"
#include "Page.h"
#include "PageGroup.h"
#include "RenderVideo.h"
#include "RenderView.h"
#include "RuntimeEnabledFeatures.h"
#include "ScriptController.h"
#include "SecurityOrigin.h"
#include "SecurityPolicy.h"
#include "Settings.h"
#include "ShadowRoot.h"
#include "TimeRanges.h"
#include <limits>
#include <runtime/TypedArrayInlines.h>
#include <runtime/Uint8Array.h>
#include <wtf/CurrentTime.h>
#include <wtf/MathExtras.h>
#include <wtf/NonCopyingSort.h>
#include <wtf/text/CString.h>

#if USE(ACCELERATED_COMPOSITING)
#include "RenderLayerCompositor.h"
#endif

#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
#include "RenderEmbeddedObject.h"
#include "Widget.h"
#endif

#if ENABLE(VIDEO_TRACK)
#include "AudioTrackList.h"
#include "AudioTrackPrivate.h"
#include "CaptionUserPreferences.h"
#include "HTMLTrackElement.h"
#include "InbandTextTrack.h"
#include "InbandTextTrackPrivate.h"
#include "RuntimeEnabledFeatures.h"
#include "TextTrackCueList.h"
#include "TextTrackList.h"
#include "VideoTrackList.h"
#include "VideoTrackPrivate.h"
#endif

#if ENABLE(WEB_AUDIO)
#include "AudioSourceProvider.h"
#include "MediaElementAudioSourceNode.h"
#endif

#if PLATFORM(MAC)
#include "DisplaySleepDisabler.h"
#endif

#if ENABLE(MEDIA_SOURCE)
#include "DOMWindow.h"
#include "HTMLMediaSource.h"
#include "Performance.h"
#include "VideoPlaybackQuality.h"
#endif

#if ENABLE(MEDIA_STREAM)
#include "MediaStream.h"
#include "MediaStreamRegistry.h"
#endif

#if ENABLE(LEGACY_ENCRYPTED_MEDIA_V2)
#include "WebKitMediaKeyNeededEvent.h"
#include "WebKitMediaKeys.h"
#endif

using namespace std;

namespace WebCore {

typedef int (*LogFunction)(const char * format, ... );

static int log_null(const char * format, ... ) { return 0; }

LogFunction gMediaLog = log_null;

DLL_PUBLIC void setHTMLMediaLogFunction(LogFunction func)
{
	gMediaLog = log_null;

	if(func)
		gMediaLog = func;
}

String urlForLogging(const KURL& url)
{
    static const unsigned maximumURLLengthForLogging = 128;

    if (url.string().length() < maximumURLLengthForLogging)
        return url.string();
    return url.string().substring(0, maximumURLLengthForLogging) + "...";
}

static const char* boolString(bool val)
{
    return val ? "true" : "false";
}

#ifndef LOG_MEDIA_EVENTS
// Default to not logging events because so many are generated they can overwhelm the rest of 
// the logging.
#define LOG_MEDIA_EVENTS 0
#endif

#ifndef LOG_CACHED_TIME_WARNINGS
// Default to not logging warnings about excessive drift in the cached media time because it adds a
// fair amount of overhead and logging.
#define LOG_CACHED_TIME_WARNINGS 0
#endif

#if ENABLE(MEDIA_SOURCE)
// URL protocol used to signal that the media source API is being used.
static const char* mediaSourceBlobProtocol = "blob";
#endif

#if ENABLE(MEDIA_STREAM)
// URL protocol used to signal that the media stream API is being used.
static const char* mediaStreamBlobProtocol = "blob";
#endif

using namespace HTMLNames;
using namespace std;

typedef HashMap<Document*, HashSet<HTMLMediaElement*> > DocumentElementSetMap;
static DocumentElementSetMap& documentToElementSetMap()
{
	static NeverDestroyed<DocumentElementSetMap> map;
    return map;
}

static void addElementToDocumentMap(HTMLMediaElement* element, Document& document)
{
    DocumentElementSetMap& map = documentToElementSetMap();
    HashSet<HTMLMediaElement*> set = map.take(&document);
    set.add(element);
    map.add(&document, set);
}

static void removeElementFromDocumentMap(HTMLMediaElement* element, Document& document)
{
    DocumentElementSetMap& map = documentToElementSetMap();
    HashSet<HTMLMediaElement*> set = map.take(&document);
    set.remove(element);
    if (!set.isEmpty())
        map.add(&document, set);
}

#if ENABLE(LEGACY_ENCRYPTED_MEDIA)
static ExceptionCode exceptionCodeForMediaKeyException(MediaPlayer::MediaKeyException exception)
{
    switch (exception) {
    case MediaPlayer::NoError:
        return 0;
    case MediaPlayer::InvalidPlayerState:
        return INVALID_STATE_ERR;
    case MediaPlayer::KeySystemNotSupported:
        return NOT_SUPPORTED_ERR;
    case MediaPlayer::InvalidKeyError:
    	return INVALID_ACCESS_ERR;
    }

    ASSERT_NOT_REACHED();
    return INVALID_STATE_ERR;
}
#endif

HTMLMediaElement::HTMLMediaElement(const QualifiedName& tagName, Document* document, bool createdByParser)
    : HTMLElement(tagName, document)
    , ActiveDOMObject(document)
    , m_loadTimer(this, &HTMLMediaElement::loadTimerFired)
    , m_progressEventTimer(this, &HTMLMediaElement::progressEventTimerFired)
    , m_playbackProgressTimer(this, &HTMLMediaElement::playbackProgressTimerFired)
	, m_pauseAfterDetachedTimer(this, &HTMLMediaElement::pauseAfterDetachedTimerFired)
	, m_seekTimer(this, &HTMLMediaElement::seekTimerFired)
    , m_playedTimeRanges()
    , m_asyncEventQueue(adoptPtr(new GenericEventQueue(*this)))
    , m_playbackRate(1.0f)
    , m_defaultPlaybackRate(1.0f)
    , m_webkitPreservesPitch(true)
    , m_networkState(NETWORK_EMPTY)
    , m_readyState(HAVE_NOTHING)
    , m_readyStateMaximum(HAVE_NOTHING)
    , m_volume(1.0f)
    , m_previousProgressTime(numeric_limits<double>::max())
    , m_clockTimeAtLastUpdateEvent(0)
	, m_lastTimeUpdateEventMovieTime(MediaTime::positiveInfiniteTime())
    , m_loadState(WaitingForSource)
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    , m_proxyWidget(0)
#endif
    , m_restrictions(RequireUserGestureForFullscreenRestriction | RequirePageConsentToLoadMediaRestriction)
    , m_preload(MediaPlayer::Auto)
    , m_displayMode(Unknown)
    , m_processingMediaPlayerCallback(0)
#if ENABLE(MEDIA_SOURCE)
    , m_droppedVideoFrames(0)
#endif
    , m_clockTimeAtLastCachedTimeUpdate(0)
    , m_minimumClockTimeToUpdateCachedTime(0)
    , m_pendingActionFlags(0)
    , m_playing(false)
    , m_isWaitingUntilMediaCanStart(false)
    , m_shouldDelayLoadEvent(false)
    , m_haveFiredLoadedData(false)
    , m_inActiveDocument(true)
    , m_autoplaying(true)
    , m_muted(false)
    , m_paused(true)
    , m_seeking(false)
    , m_sentStalledEvent(false)
    , m_sentEndEvent(false)
    , m_pausedInternal(false)
    , m_sendProgressEvents(true)
    , m_isFullscreen(false)
    , m_closedCaptionsVisible(false)
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    , m_needWidgetUpdate(false)
#endif
    , m_dispatchingCanPlayEvent(false)
    , m_loadInitiatedByUserGesture(false)
    , m_completelyLoaded(false)
    , m_havePreparedToPlay(false)
    , m_parsingInProgress(createdByParser)
#if ENABLE(VIDEO_TRACK)
    , m_tracksAreReady(true)
    , m_haveVisibleTextTrack(false)
    , m_lastTextTrackUpdateTime(-1)
    , m_ignoreTrackDisplayUpdate(0)
	, m_disableCaptions(false)
#endif
#if ENABLE(WEB_AUDIO)
    , m_audioSourceNode(0)
#endif
#if ENABLE(LEGACY_ENCRYPTED_MEDIA)
	, m_keyRequestTimer(this, &HTMLMediaElement::keyRequestTimerFired)
#endif
#if ENABLE(MEDIA_STREAM)
    , m_mediaStreamSrcObject(nullptr)
#endif
{
    gMediaLog("HTMLMediaElement(%p)::HTMLMediaElement()\n", this);
    setHasCustomStyleResolveCallbacks();

    document->registerForDocumentActivationCallbacks(*this);
    document->registerForMediaVolumeCallbacks(*this);
    document->registerForPrivateBrowsingStateChangedCallbacks(*this);
    
    if (document->settings().mediaPlaybackRequiresUserGesture()) {
        addBehaviorRestriction(RequireUserGestureForRateChangeRestriction);
        addBehaviorRestriction(RequireUserGestureForLoadRestriction);
    }

    addElementToDocumentMap(this, *document);

#if ENABLE(VIDEO_TRACK)
    document->registerForCaptionPreferencesChangedCallbacks(*this);
    if (document->page()) {
        PageGroup& group = document->page()->group();
        if (group.userHasCaptionPreferences())
            m_disableCaptions = !group.userPrefersCaptions();
    }
#endif
}

HTMLMediaElement::~HTMLMediaElement()
{
    gMediaLog("HTMLMediaElement(%p)::~HTMLMediaElement()\n", this);

    m_asyncEventQueue->close();

    if (m_isWaitingUntilMediaCanStart)
        document().removeMediaCanStartListener(this);
    setShouldDelayLoadEvent(false);
    document().unregisterForDocumentActivationCallbacks(*this);
    document().unregisterForMediaVolumeCallbacks(*this);
    document().unregisterForPrivateBrowsingStateChangedCallbacks(*this);
#if ENABLE(VIDEO_TRACK)
    document().unregisterForCaptionPreferencesChangedCallbacks(*this);
    if (m_audioTracks) {
        m_audioTracks->clearElement();
        for (unsigned i = 0; i < m_audioTracks->length(); ++i)
            m_audioTracks->item(i)->clearClient();
    }
    if (m_textTracks){
        m_textTracks->clearElement();
        for (unsigned i = 0; i < m_textTracks->length(); ++i)
            m_textTracks->item(i)->clearClient();
    }
    if (m_videoTracks) {
        m_videoTracks->clearElement();
        for (unsigned i = 0; i < m_videoTracks->length(); ++i)
            m_videoTracks->item(i)->clearClient();
    }
#endif

    if (m_mediaController) {
        m_mediaController->removeMediaElement(this);
        m_mediaController = nullptr;
    }

#if ENABLE(MEDIA_SOURCE)
    detachMediaSource();
#endif

#if ENABLE(LEGACY_ENCRYPTED_MEDIA_V2)
    webkitSetMediaKeys(0);
#endif

    removeElementFromDocumentMap(this, document());
}

void HTMLMediaElement::didMoveToNewDocument(Document& oldDocument, Document& newDocument)
{
    ASSERT_WITH_SECURITY_IMPLICATION(&document() == &newDocument);
    if (m_isWaitingUntilMediaCanStart) {
        oldDocument.removeMediaCanStartListener(this);
        newDocument.addMediaCanStartListener(this);
    }

    if (m_shouldDelayLoadEvent) {
        oldDocument.decrementLoadEventDelayCount();
        newDocument.incrementLoadEventDelayCount();
    }

    oldDocument.unregisterForDocumentActivationCallbacks(*this);
    oldDocument.unregisterForMediaVolumeCallbacks(*this);
    removeElementFromDocumentMap(this, oldDocument);

    newDocument.registerForDocumentActivationCallbacks(*this);
    newDocument.registerForMediaVolumeCallbacks(*this);
    addElementToDocumentMap(this, newDocument);

    HTMLElement::didMoveToNewDocument(oldDocument, newDocument);
}

bool HTMLMediaElement::supportsFocus() const
{
    if (document().isMediaDocument())
        return false;

    // If no controls specified, we should still be able to focus the element if it has tabIndex.
    return controls() ||  HTMLElement::supportsFocus();
}

bool HTMLMediaElement::isMouseFocusable() const
{
    return false;
}

bool HTMLMediaElement::isInteractiveContent() const
{
    return controls();
}

void HTMLMediaElement::attributeChanged(const QualifiedName& name, const AtomString& oldValue, const AtomString& newValue, AttributeModificationReason attributeModificationReason)
{
	if(m_player)
		m_player->attributeChanged(name.localName(), newValue);

    if (name == srcAttr) {
        // Trigger a reload, as long as the 'src' attribute is present.
    	if (!newValue.isNull()) {
    	    gMediaLog("HTMLMediaElement(%p)::attributeChanged(src is %s, inDocument %i) at %f\n", this, newValue.string().latin1().data(), inDocument(), WTF::currentTime());
    	    clearMediaPlayer(LoadMediaResource, true);
    	    scheduleDelayedAction(LoadMediaResource);
    	}
    	else{
    	    gMediaLog("HTMLMediaElement(%p)::attributeChanged(src is null)\n", this);
    	}
    } else if (name == controlsAttr)
        configureMediaControls();
#if PLATFORM(MAC)
    else if (name == loopAttr)
        updateDisableSleep();
#endif
    else if (name == preloadAttr) {
        if (equalLettersIgnoringASCIICase(newValue, "none"))
            m_preload = MediaPlayer::None;
        else if (equalLettersIgnoringASCIICase(newValue, "metadata"))
            m_preload = MediaPlayer::MetaData;
        else {
            // The spec does not define an "invalid value default" but "auto" is suggested as the
            // "missing value default", so use it for everything except "none" and "metadata"
            m_preload = MediaPlayer::Auto;
        }

        // The attribute must be ignored if the autoplay attribute is present
        if (!autoplay() && m_player)
            m_player->setPreload(m_preload);

    } else if (name == mediagroupAttr) {
		if(document().settings().mediaControllerEnabled())
			setMediaGroup(newValue);
		else
			gMediaLog("HTMLMediaElement(%p)::setMediaGroup(%s) controller is disabled.\n", this, newValue.string().utf8().data());
    }
#if ENABLE(WIRELESS_PLAYBACK_TARGET)
    else if (name == webkitwirelessvideoplaybackdisabledAttr)
        mediaSession().setWirelessVideoPlaybackDisabled(newValue != nullAtom());
#endif
    else
        HTMLElement::attributeChanged(name, oldValue, newValue, attributeModificationReason);
}

void HTMLMediaElement::finishParsingChildren()
{
    HTMLElement::finishParsingChildren();
    m_parsingInProgress = false;

#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    document().updateStyleIfNeeded();
    createMediaPlayerProxy();
#endif
    
#if ENABLE(VIDEO_TRACK)
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    if (Traversal<HTMLTrackElement>::firstWithin(this))
    	scheduleDelayedAction(LoadTextTrackResource);
#endif
}

bool HTMLMediaElement::rendererIsNeeded(const RenderStyle& style)
{
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    UNUSED_PARAM(style);
    Frame* frame = document().frame();
    if (!frame)
        return false;

    return true;
#else
    return controls() && HTMLElement::rendererIsNeeded(style);
#endif
}

RenderPtr<RenderElement> HTMLMediaElement::createElementRenderer(PassOwnPtr<RenderStyle> style, const RenderTreePosition&)
{
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    // Setup the renderer if we already have a proxy widget.
    auto mediaRenderer = createRenderer<RenderEmbeddedObject>(*this, style);
    if (m_proxyWidget) {
        mediaRenderer->setWidget(m_proxyWidget);

        if (Frame* frame = document().frame())
            frame->loader()->client()->showMediaPlayerProxyPlugin(m_proxyWidget.get());
    }
    return WTFMove(mediaRenderer);
#else
    return createRenderer<RenderMedia>(*this, style);
#endif
}

bool HTMLMediaElement::childShouldCreateRenderer(const Node* child) const
{
    if (!hasMediaControls())
        return false;
    // <media> doesn't allow its content, including shadow subtree, to
    // be rendered. So this should return false for most of the children.
    // One exception is a shadow tree built for rendering controls which should be visible.
    // So we let them go here by comparing its subtree root with one of the controls.
    return (&mediaControls()->treeScope() == &child->treeScope()
            && hasShadowRootParent(child)
			&& HTMLElement::childShouldCreateRenderer(child));
}

Node::InsertedIntoResult HTMLMediaElement::insertedIntoAncestor(const InsertionType& insertionType, ContainerNode& parentOfInsertedTree)
{
    gMediaLog("HTMLMediaElement(%p)::insertedIntoAncestor\n", this);

    HTMLElement::insertedIntoAncestor(insertionType, parentOfInsertedTree);
    if (insertionType.connectedToDocument) {
		m_inActiveDocument = true;

		if (m_networkState == NETWORK_EMPTY && !getAttribute(srcAttr).isEmpty())
			scheduleDelayedAction(LoadMediaResource);
    }

    return InsertedIntoResult::NeedsPostInsertionCallback;
}

void HTMLMediaElement::didFinishInsertingNode()
{
    configureMediaControls();
}

void HTMLMediaElement::pauseAfterDetachedTimerFired()
{
    // If we were re-inserted into an active document, no need to pause.
    if (m_inActiveDocument)
        return;
	if (hasMediaControls())
		mediaControls()->hide();
#if 0
	if (m_networkState > NETWORK_EMPTY)
		pause();
#else
	clearMediaPlayer(LoadMediaResource, false);
	m_networkState = NETWORK_EMPTY;
#endif
	if (m_isFullscreen)
		exitFullscreen();

    if (!m_player)
        return;

#if 0
	size_t extraMemoryCost = m_player->extraMemoryCost();
	if (extraMemoryCost > m_reportedExtraMemoryCost) {
		JSC::VM& vm = JSDOMWindowBase::commonVM();
		JSC::JSLockHolder lock(vm);

		size_t extraMemoryCostDelta = extraMemoryCost - m_reportedExtraMemoryCost;
		m_reportedExtraMemoryCost = extraMemoryCost;

		// FIXME: Adopt reportExtraMemoryVisited, and switch to reportExtraMemoryAllocated.
		// https://bugs.webkit.org/show_bug.cgi?id=142595
		vm.heap.deprecatedReportExtraMemory(extraMemoryCostDelta);
	}

#endif
}

void HTMLMediaElement::removedFromAncestor(const RemovalType& removalType, ContainerNode& parentOfRemovedTree)
{
    LOG(Media, "HTMLMediaElement::removedFromAncestor(%p)", this);

    m_inActiveDocument = false;
    if (removalType.disconnectedFromDocument) {
        // Pause asynchronously to let the operation that removed us finish, in case we get inserted back into a document.
        m_pauseAfterDetachedTimer.startOneShot(0);
    }

    HTMLElement::removedFromAncestor(removalType, parentOfRemovedTree);
}

void HTMLMediaElement::willAttachRenderers()
{
    ASSERT(!renderer());

#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    m_needWidgetUpdate = true;
#endif
}

void HTMLMediaElement::didAttachRenderers()
{
    if (renderer())
        renderer()->updateFromElement();
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    else if (m_proxyWidget) {
        if (Frame* frame = document().frame())
            frame->loader()->client()->hideMediaPlayerProxyPlugin(m_proxyWidget.get());
    }
#endif
}

void HTMLMediaElement::didRecalcStyle(Style::Change)
{
    if (renderer())
        renderer()->updateFromElement();
}

void HTMLMediaElement::scheduleDelayedAction(DelayedActionType loadType)
{
    gMediaLog("HTMLMediaElement(%p)::scheduleDelayedAction\n", this);

    if ((loadType & LoadMediaResource) && !(m_pendingActionFlags & LoadMediaResource)) {
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
        createMediaPlayerProxy();
#endif
        
        prepareForLoad();
        m_pendingActionFlags |= LoadMediaResource;
    }

#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled() && (loadType & LoadTextTrackResource))
    	m_pendingActionFlags |= LoadTextTrackResource;
#endif

    if (!m_loadTimer.isActive())
        m_loadTimer.startOneShot(0);
}

void HTMLMediaElement::scheduleNextSourceChild()
{
    // Schedule the timer to try the next <source> element WITHOUT resetting state ala prepareForLoad.
	m_pendingActionFlags |= LoadMediaResource;
    m_loadTimer.startOneShot(0);
}

void HTMLMediaElement::scheduleEvent(const AtomicString& eventName)
{
#if LOG_MEDIA_EVENTS
    gMediaLog("HTMLMediaElement(%p)::scheduleEvent - scheduling '%s'\n", this, eventName.string().ascii().data());
#endif
    RefPtr<Event> event = Event::create(eventName, false, true);

    // Don't set the event target, the event queue will set it in GenericEventQueue::timerFired and setting it here
    // will trigger an ASSERT if this element has been marked for deletion.

    m_asyncEventQueue->enqueueEvent(event.release());
}

void HTMLMediaElement::loadTimerFired()
{
    RefPtr<HTMLMediaElement> protect(this); // loadNextSourceChild may fire 'beforeload', which can make arbitrary DOM mutations.

#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled() && (m_pendingActionFlags & LoadTextTrackResource))
        configureTextTracks();
#endif

    if (m_pendingActionFlags & LoadMediaResource) {
        if (m_loadState == LoadingFromSourceElement)
            loadNextSourceChild();
        else
            loadInternal();
    }

    m_pendingActionFlags = 0;
}

PassRefPtr<MediaError> HTMLMediaElement::error() const 
{
    return m_error;
}

void HTMLMediaElement::setSrc(const String& url)
{
    setAttribute(srcAttr, url);
}

#if ENABLE(MEDIA_STREAM)
void HTMLMediaElement::setSrcObject(MediaStream* mediaStream)
{
    // FIXME: Setting the srcObject attribute may cause other changes to the media element's internal state:
    // Specifically, if srcObject is specified, the UA must use it as the source of media, even if the src
    // attribute is also set or children are present. If the value of srcObject is replaced or set to null
    // the UA must re-run the media element load algorithm.
    //
    // https://bugs.webkit.org/show_bug.cgi?id=124896

    m_mediaStreamSrcObject = mediaStream;
}
#endif

HTMLMediaElement::NetworkState HTMLMediaElement::networkState() const
{
    return m_networkState;
}

String HTMLMediaElement::canPlayType(const String& mimeType, const String& keySystem, const KURL& url) const
{
    MediaEngineSupportParameters parameters;
    ContentType contentType(mimeType);
    parameters.type = contentType.type().lower();
    parameters.codecs = contentType.parameter(ASCIILiteral("codecs"));
    parameters.url = url;
#if ENABLE(ENCRYPTED_MEDIA)
    parameters.keySystem = keySystem;
#else
    UNUSED_PARAM(keySystem);
#endif
    MediaPlayer::SupportsType support = MediaPlayer::supportsType(parameters, this);

    if (support == MediaPlayer::IsNotSupported) {
        // Try with Media Source:
    	parameters.isMediaSource = true;
    	support = MediaPlayer::supportsType(parameters, this);
    }

    String canPlay;

    // 4.8.10.3
    switch (support)
    {
		case MediaPlayer::IsNotSupported:
			canPlay = emptyString();
			break;
		case MediaPlayer::MayBeSupported:
			canPlay = String("maybe", String::ConstructFromLiteral);
			break;
		case MediaPlayer::IsSupported:
			canPlay = String("probably", String::ConstructFromLiteral);
			break;
    }
    
    gMediaLog("HTMLMediaElement(%p)::canPlayType(%s, %s, %s) -> %s\n", this, mimeType.utf8().data(), keySystem.utf8().data(), url.string().utf8().data(), canPlay.utf8().data());

    return canPlay;
}

double HTMLMediaElement::getStartDate() const
{
    if (!m_player)
        return std::numeric_limits<double>::quiet_NaN();
    return m_player->getStartDate().toDouble();
}

void HTMLMediaElement::load(ExceptionCode& ec)
{
    RefPtr<HTMLMediaElement> protect(this); // loadInternal may result in a 'beforeload' event, which can make arbitrary DOM mutations.
    
    gMediaLog("HTMLMediaElement(%p)::load() at %f\n", this, WTF::currentTime());
    
    if (userGestureRequiredForLoad() && !ScriptController::processingUserGesture()) {
        ec = INVALID_STATE_ERR;
        return;
    }
    
    m_loadInitiatedByUserGesture = ScriptController::processingUserGesture();
    if (m_loadInitiatedByUserGesture)
        removeBehaviorsRestrictionsAfterFirstUserGesture();
    prepareForLoad();
    loadInternal();
    prepareToPlay();
}

int HTMLMediaElement::mediaPlayerID() const
{
    if (m_player)
        return m_player->mediaPlayerID();
    return -1;
}

void HTMLMediaElement::prepareForLoad()
{
    gMediaLog("HTMLMediaElement(%p)::prepareForLoad\n", this);

    // Perform the cleanup required for the resource load algorithm to run.
    stopPeriodicTimers();
    m_loadTimer.stop();
    m_sentEndEvent = false;
    m_sentStalledEvent = false;
    m_haveFiredLoadedData = false;
    m_completelyLoaded = false;
    m_havePreparedToPlay = false;
    m_displayMode = Unknown;

    // 1 - Abort any already-running instance of the resource selection algorithm for this element.
    m_loadState = WaitingForSource;
    m_currentSourceNode = 0;

    if (!document().hasBrowsingContext())
        return;

    // 2 - If there are any tasks from the media element's media element event task source in 
    // one of the task queues, then remove those tasks.
    cancelPendingEventsAndCallbacks();

    // 3 - If the media element's networkState is set to NETWORK_LOADING or NETWORK_IDLE, queue
    // a task to fire a simple event named abort at the media element.
    if (m_networkState == NETWORK_LOADING || m_networkState == NETWORK_IDLE)
        scheduleEvent(eventNames().abortEvent);

#if ENABLE(MEDIA_SOURCE)
    detachMediaSource();
#endif

#if !ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    createMediaPlayer();
#else
    if (m_player)
        m_player->cancelLoad();
    else
        createMediaPlayerProxy();
#endif

    // 4 - If the media element's networkState is not set to NETWORK_EMPTY, then run these substeps
    if (m_networkState != NETWORK_EMPTY) {
        m_networkState = NETWORK_EMPTY;
        m_readyState = HAVE_NOTHING;
        m_readyStateMaximum = HAVE_NOTHING;
        refreshCachedTime();
        m_paused = true;
        m_seeking = false;
        invalidateCachedTime();
        scheduleEvent(eventNames().emptiedEvent);
        updateMediaController();
#if ENABLE(VIDEO_TRACK)
        if (RuntimeEnabledFeatures::webkitVideoTrackEnabled())
            updateActiveTextTrackCues(0);
#endif
    }

    // 5 - Set the playbackRate attribute to the value of the defaultPlaybackRate attribute.
    setPlaybackRate(defaultPlaybackRate());

    // 6 - Set the error attribute to null and the autoplaying flag to true.
    m_error = 0;
    m_autoplaying = true;

    // 7 - Invoke the media element's resource selection algorithm.

    // 8 - Note: Playback of any previously playing media resource for this element stops.

    // The resource selection algorithm
    // 1 - Set the networkState to NETWORK_NO_SOURCE
    m_networkState = NETWORK_NO_SOURCE;

    // 2 - Asynchronously await a stable state.

    m_playedTimeRanges = TimeRanges::create();

    // FIXME: Investigate whether these can be moved into m_networkState != NETWORK_EMPTY block above
    // so they are closer to the relevant spec steps.
    m_lastSeekTime = MediaTime::zeroTime();

    // The spec doesn't say to block the load event until we actually run the asynchronous section
    // algorithm, but do it now because we won't start that until after the timer fires and the 
    // event may have already fired by then.
    setShouldDelayLoadEvent(true);

    configureMediaControls();
}

void HTMLMediaElement::loadInternal()
{
    // Some of the code paths below this function dispatch the BeforeLoad event. This ASSERT helps
    // us catch those bugs more quickly without needing all the branches to align to actually
    // trigger the event.
    ASSERT(!eventDispatchForbidden());

    // If we can't start a load right away, start it later.
    Page* page = document().page();
    if (pageConsentRequiredForLoad() && page && !page->canStartMedia()) {
        setShouldDelayLoadEvent(false);
        if (m_isWaitingUntilMediaCanStart)
            return;
        document().addMediaCanStartListener(this);
        m_isWaitingUntilMediaCanStart = true;
        return;
    }
    
    m_pendingActionFlags &= ~LoadMediaResource;

    // Once the page has allowed an element to load media, it is free to load at will. This allows a 
    // playlist that starts in a foreground tab to continue automatically if the tab is subsequently 
    // put in the the background.
    removeBehaviorRestriction(RequirePageConsentToLoadMediaRestriction);

#if ENABLE(VIDEO_TRACK)
    // HTMLMediaElement::textTracksAreReady will need "... the text tracks whose mode was not in the
    // disabled state when the element's resource selection algorithm last started".
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled()) {
        m_textTracksWhenResourceSelectionBegan.clear();
        if (m_textTracks) {
            for (unsigned i = 0; i < m_textTracks->length(); ++i) {
                TextTrack* track = m_textTracks->item(i);
                if (track->mode() != TextTrack::disabledKeyword())
                    m_textTracksWhenResourceSelectionBegan.append(track);
            }
        }
    }
#endif

    selectMediaResource();
}

void HTMLMediaElement::selectMediaResource()
{
    gMediaLog("HTMLMediaElement(%p)::selectMediaResource [inDocument %i]\n", this, inDocument());

    enum Mode { attribute, children };

    // 3 - If the media element has a src attribute, then let mode be attribute.
    Mode mode = attribute;

    const KURL mediaURL(getNonEmptyURLAttribute(srcAttr));

    if (!hasAttributeWithoutSynchronization(srcAttr) || mediaURL.isEmpty()) {
        Node* node;
        for (node = firstChild(); node; node = node->nextSibling()) {
            if (node->hasTagName(sourceTag))
                break;
        }

        // Otherwise, if the media element does not have a src attribute but has a source 
        // element child, then let mode be children and let candidate be the first such 
        // source element child in tree order.
        if (node) {
            mode = children;
            m_nextChildNodeToConsider = node;
            m_currentSourceNode = 0;
        } else {
            // Otherwise the media element has neither a src attribute nor a source element 
            // child: set the networkState to NETWORK_EMPTY, and abort these steps; the 
            // synchronous section ends.
            m_loadState = WaitingForSource;
            setShouldDelayLoadEvent(false);
            m_networkState = NETWORK_EMPTY;

    	    if(m_player){
    	    	m_player->clearMediaPlayerClient();
    	    	m_player.clear();
    	    }

            gMediaLog("HTMLMediaElement(%p)::selectMediaResource, nothing to load\n", this);
            return;
        }
    }

    // 4 - Set the media element's delaying-the-load-event flag to true (this delays the load event), 
    // and set its networkState to NETWORK_LOADING.
    setShouldDelayLoadEvent(true);

    m_networkState = NETWORK_IDLE;
    scheduleEvent(eventNames().suspendEvent);

    // 6 - If mode is attribute, then run these substeps
    if (mode == attribute) {
        m_loadState = LoadingFromSrcAttr;

        // If the src attribute's value is the empty string ... jump down to the failed step below
        if (mediaURL.isEmpty()) {
            mediaLoadingFailed(MediaPlayer::FormatError);
            gMediaLog("HTMLMediaElement(%p)::selectMediaResource, empty 'src'\n", this);
            return;
        }

        if (!isSafeToLoadURL(mediaURL, Complain)) {
            mediaLoadingFailed(MediaPlayer::FormatError);
            return;
        }

        // No type or key system information is available when the url comes
        // from the 'src' attribute so MediaPlayer
        // will have to pick a media engine based on the file extension.
        ContentType contentType((String()));
        loadResource(mediaURL, contentType, String());
        gMediaLog("HTMLMediaElement(%p)::selectMediaResource, using 'src' attribute url\n", this);
        return;
    }

    // Otherwise, the source elements will be used
    loadNextSourceChild();
}

void HTMLMediaElement::loadNextSourceChild()
{
    ContentType contentType((String()));
    String keySystem;
    KURL mediaURL = selectNextSourceChild(&contentType, &keySystem, Complain);
    if (!mediaURL.isValid()) {
        waitForSourceChange();
        return;
    }

#if !ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    // Recreate the media player for the new url
    createMediaPlayer();
#endif

    m_loadState = LoadingFromSourceElement;
    loadResource(mediaURL, contentType, keySystem);
}

#if !PLATFORM(CHROMIUM)
static KURL createFileURLForApplicationCacheResource(const String& path)
{
    // KURL should have a function to create a url from a path, but it does not. This function
    // is not suitable because KURL::setPath uses encodeWithURLEscapeSequences, which it notes
    // does not correctly escape '#' and '?'. This function works for our purposes because
    // app cache media files are always created with encodeForFileName(createVersion4UUIDString()).

#if USE(CF) && PLATFORM(WIN)
    RetainPtr<CFStringRef> cfPath(AdoptCF, path.createCFString());
    RetainPtr<CFURLRef> cfURL(AdoptCF, CFURLCreateWithFileSystemPath(0, cfPath.get(), kCFURLWindowsPathStyle, false));
    KURL url(cfURL.get());
#else
    KURL url;

    url.setProtocol("file");
    url.setPath(path);
#endif
    return url;
}
#endif

void HTMLMediaElement::loadResource(const KURL& initialURL, ContentType& contentType, const String& keySystem)
{
    ASSERT(isSafeToLoadURL(initialURL, Complain));

    gMediaLog("HTMLMediaElement(%p)::loadResource(%s, %s, %s)\n", this, urlForLogging(initialURL).utf8().data(), contentType.raw().utf8().data(), keySystem.utf8().data());

    Frame* frame = document().frame();
    if (!frame) {
        mediaLoadingFailed(MediaPlayer::FormatError);
        return;
    }

    KURL url = initialURL;
    if (!frame->loader()->willLoadMediaElementURL(url)) {
        mediaLoadingFailed(MediaPlayer::FormatError);
        return;
    }

#if ENABLE(CONTENT_EXTENSIONS)
    DocumentLoader* documentLoader = frame->loader().documentLoader();

    if (documentLoader) {
        auto blockedStatus = page->userContentProvider().processContentExtensionRulesForLoad(url, ResourceType::Media, *documentLoader);
        if (blockedStatus.blockedLoad) {
            mediaLoadingFailed(MediaPlayer::FormatError);
            return;
        }
    }
#endif
    
    // If the url should be loaded from the application cache, pass the url of the cached file
    // to the media engine.
    ApplicationCacheHost& cacheHost = frame->loader()->documentLoader()->applicationCacheHost();
    ApplicationCacheResource* resource = 0;
    if (cacheHost.shouldLoadResourceFromApplicationCache(ResourceRequest(url), resource)) {
        // Resources that are not present in the manifest will always fail to load (at least, after the
        // cache has been primed the first time), making the testing of offline applications simpler.
        if (!resource || resource->path().isEmpty()) {
            mediaLoadingFailed(MediaPlayer::NetworkError);
            return;
        }
    }

    // Set m_currentSrc *before* changing to the cache url, the fact that we are loading from the app
    // cache is an internal detail not exposed through the media element API.
    m_currentSrc = url;

    if (resource) {
        url = createFileURLForApplicationCacheResource(resource->path());
        gMediaLog("HTMLMediaElement(%p)::loadResource - will load from app cache -> %s\n", this, urlForLogging(url).utf8().data());
    }

    gMediaLog("HTMLMediaElement(%p)::loadResource - m_currentSrc -> %s\n", this, urlForLogging(m_currentSrc).utf8().data());

    if (m_sendProgressEvents) 
        startProgressEventTimer();

    bool privateMode = document().settings().privateBrowsingEnabled();
    m_player->setPrivateBrowsingMode(privateMode);

    // Reset display mode to force a recalculation of what to show because we are resetting the player.
    setDisplayMode(Unknown);

    if (!autoplay())
        m_player->setPreload(m_preload);
    m_player->setPreservesPitch(m_webkitPreservesPitch);

    if (hasAttributeWithoutSynchronization(mutedAttr))
        m_muted = true;
    updateVolume();

    bool loadAttempted = false;
#if ENABLE(MEDIA_SOURCE)
    ASSERT(!m_mediaSource);

    if (url.protocolIs(mediaSourceBlobProtocol))
        m_mediaSource = HTMLMediaSource::lookup(url.string());

    if (m_mediaSource) {
        gMediaLog("HTMLMediaElement(%p)::loadResource - m_mediaSource -> %p\n", this, m_mediaSource.get());

    	m_mediaSource->registry().unregisterURL(url);

        if (!m_mediaSource->attachToElement(*this)) {
            // Forget our reference to the MediaSource, so we leave it alone
            // while processing remainder of load failure.
            m_mediaSource = nullptr;
#if ENABLE(LEGACY_ENCRYPTED_MEDIA)
            m_pendingKeyRequests.clear();
#endif
            mediaLoadingFailed(MediaPlayer::FormatError);
        } else if(!m_player->load(url, m_mediaSource)) {
            // We have to detach the MediaSource before we forget the reference to it.
            m_mediaSource->detachFromElement(*this);
            m_mediaSource = nullptr;
            mediaLoadingFailed(MediaPlayer::FormatError);
        } else {
#if ENABLE(LEGACY_ENCRYPTED_MEDIA)
			if(m_pendingKeyRequests.size() > 0 && !m_keyRequestTimer.isActive())
				m_keyRequestTimer.startOneShot(0);
#endif
		}
        loadAttempted = true;
    }
#endif

#if ENABLE(MEDIA_STREAM)
    if (!loadAttempted) {
        if (!m_mediaStreamSrcObject && url.protocolIs(mediaStreamBlobProtocol))
            m_mediaStreamSrcObject = MediaStream::lookUp(url);

        if (m_mediaStreamSrcObject) {
            loadAttempted = true;
            if (!m_player->load(m_mediaStreamSrcObject->privateStream()))
                mediaLoadingFailed(MediaPlayer::FormatError);
        }
    }
#endif

    if (!loadAttempted) {
        MediaFragmentURIParser fragmentParser(m_currentSrc);

        MediaTime start = fragmentParser.startTime();
        double fragmentStartTime = 0.0;
        if (start.isValid() && start > MediaTime::zeroTime())
        	fragmentStartTime = start.toDouble();

    	if (!m_player->load(url, contentType, keySystem, fragmentStartTime))
    		mediaLoadingFailed(MediaPlayer::FormatError);

#if ENABLE(LEGACY_ENCRYPTED_MEDIA)
        m_pendingKeyRequests.clear();
#endif
    }

    m_player->setClosedCaptionsVisible(m_closedCaptionsVisible);

    // If there is no poster to display, allow the media engine to render video frames as soon as
    // they are available.
    updateDisplayState();

    if (renderer())
        renderer()->updateFromElement();
}

#if ENABLE(VIDEO_TRACK)
static bool trackIndexCompare(TextTrack* a,
                              TextTrack* b)
{
    return a->trackIndex() - b->trackIndex() < 0;
}

static bool eventTimeCueCompare(const std::pair<double, TextTrackCue*>& a,
                                const std::pair<double, TextTrackCue*>& b)
{
    // 12 - Sort the tasks in events in ascending time order (tasks with earlier
    // times first).
    if (a.first != b.first)
        return a.first - b.first < 0;

    // If the cues belong to different text tracks, it doesn't make sense to
    // compare the two tracks by the relative cue order, so return the relative
    // track order.
    if (a.second->track() != b.second->track())
        return trackIndexCompare(a.second->track(), b.second->track());

    // 12 - Further sort tasks in events that have the same time by the
    // relative text track cue order of the text track cues associated
    // with these tasks.
    return a.second->cueIndex() - b.second->cueIndex() < 0;
}


void HTMLMediaElement::updateActiveTextTrackCues(double movieTime)
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled() || !m_textTracks)
        return;

    // 4.8.10.8 Playing the media resource

    //  If the current playback position changes while the steps are running,
    //  then the user agent must wait for the steps to complete, and then must
    //  immediately rerun the steps.
    if (ignoreTrackDisplayUpdateRequests())
        return;

    // 1 - Let current cues be a list of cues, initialized to contain all the
    // cues of all the hidden, showing, or showing by default text tracks of the
    // media element (not the disabled ones) whose start times are less than or
    // equal to the current playback position and whose end times are greater
    // than the current playback position.
    CueList currentCues;

    // The user agent must synchronously unset [the text track cue active] flag
    // whenever ... the media element's readyState is changed back to HAVE_NOTHING.
    if (m_readyState != HAVE_NOTHING && m_player)
        currentCues = m_cueTree.allOverlaps(m_cueTree.createInterval(movieTime, movieTime));

    CueList previousCues;
    CueList missedCues;

    // 2 - Let other cues be a list of cues, initialized to contain all the cues
    // of hidden, showing, and showing by default text tracks of the media
    // element that are not present in current cues.
    previousCues = m_currentlyActiveCues;

    // 3 - Let last time be the current playback position at the time this
    // algorithm was last run for this media element, if this is not the first
    // time it has run.
    double lastTime = m_lastTextTrackUpdateTime;

    // 4 - If the current playback position has, since the last time this
    // algorithm was run, only changed through its usual monotonic increase
    // during normal playback, then let missed cues be the list of cues in other
    // cues whose start times are greater than or equal to last time and whose
    // end times are less than or equal to the current playback position.
    // Otherwise, let missed cues be an empty list.
    if (lastTime >= 0 && m_lastSeekTime.toDouble() < movieTime) {
    	CueList potentiallySkippedCues =
            m_cueTree.allOverlaps(m_cueTree.createInterval(lastTime, movieTime));

        for (size_t i = 0; i < potentiallySkippedCues.size(); ++i) {
            double cueStartTime = potentiallySkippedCues[i].low();
            double cueEndTime = potentiallySkippedCues[i].high();

            // Consider cues that may have been missed since the last seek time.
            if (cueStartTime > max(m_lastSeekTime.toDouble(), lastTime) && cueEndTime < movieTime)
                missedCues.append(potentiallySkippedCues[i]);
        }
    }

    m_lastTextTrackUpdateTime = movieTime;

    // 5 - If the time was reached through the usual monotonic increase of the
    // current playback position during normal playback, and if the user agent
    // has not fired a timeupdate event at the element in the past 15 to 250ms
    // and is not still running event handlers for such an event, then the user
    // agent must queue a task to fire a simple event named timeupdate at the
    // element. (In the other cases, such as explicit seeks, relevant events get
    // fired as part of the overall process of changing the current playback
    // position.)
    if (m_lastSeekTime.toDouble() <= lastTime)
        scheduleTimeupdateEvent(false);

    // Explicitly cache vector sizes, as their content is constant from here.
    size_t currentCuesSize = currentCues.size();
    size_t missedCuesSize = missedCues.size();
    size_t previousCuesSize = previousCues.size();

    //gMediaLog("HTMLMediaElement(%p)::updateActiveTextTrackCues(movieTime %f) Cues size [current %i, missed %i, previous %i]\n",
    //		this, movieTime, currentCuesSize, missedCuesSize, previousCuesSize);

    // 6 - If all of the cues in current cues have their text track cue active
    // flag set, none of the cues in other cues have their text track cue active
    // flag set, and missed cues is empty, then abort these steps.
    bool activeSetChanged = missedCuesSize;

    for (size_t i = 0; !activeSetChanged && i < previousCuesSize; ++i)
        if (!currentCues.contains(previousCues[i]) && previousCues[i].data()->isActive())
            activeSetChanged = true;

    for (size_t i = 0; i < currentCuesSize; ++i) {
        currentCues[i].data()->updateDisplayTree(movieTime);

        if (!currentCues[i].data()->isActive())
            activeSetChanged = true;
    }

    if (!activeSetChanged){
        // Even though the active set has not changed, it is possible that the
        // the mode of a track has changed from 'hidden' to 'showing' and the
        // cues have not yet been rendered.
        // Note: don't call updateTextTrackDisplay() unless we have controls because it will
        // create them.
        if (hasMediaControls())
            updateTextTrackDisplay();
        return;
    }

    // 7 - If the time was reached through the usual monotonic increase of the
    // current playback position during normal playback, and there are cues in
    // other cues that have their text track cue pause-on-exi flag set and that
    // either have their text track cue active flag set or are also in missed
    // cues, then immediately pause the media element.
    for (size_t i = 0; !m_paused && i < previousCuesSize; ++i) {
        if (previousCues[i].data()->pauseOnExit()
            && previousCues[i].data()->isActive()
            && !currentCues.contains(previousCues[i]))
            pause();
    }

    for (size_t i = 0; !m_paused && i < missedCuesSize; ++i) {
        if (missedCues[i].data()->pauseOnExit())
            pause();
    }

    // 8 - Let events be a list of tasks, initially empty. Each task in this
    // list will be associated with a text track, a text track cue, and a time,
    // which are used to sort the list before the tasks are queued.
    Vector<std::pair<double, TextTrackCue*> > eventTasks;

    // 8 - Let affected tracks be a list of text tracks, initially empty.
    Vector<TextTrack*> affectedTracks;

    for (size_t i = 0; i < missedCuesSize; ++i) {
        // 9 - For each text track cue in missed cues, prepare an event named enter
        // for the TextTrackCue object with the text track cue start time.
        eventTasks.append(std::make_pair(missedCues[i].data()->startTime(),
                                         missedCues[i].data()));

        // 10 - For each text track [...] in missed cues, prepare an event
        // named exit for the TextTrackCue object with the  with the later of
        // the text track cue end time and the text track cue start time.

        // Note: An explicit task is added only if the cue is NOT a zero or
        // negative length cue. Otherwise, the need for an exit event is
        // checked when these tasks are actually queued below. This doesn't
        // affect sorting events before dispatch either, because the exit
        // event has the same time as the enter event.
        if (missedCues[i].data()->startTime() < missedCues[i].data()->endTime())
            eventTasks.append(std::make_pair(missedCues[i].data()->endTime(),
                                             missedCues[i].data()));
    }

    for (size_t i = 0; i < previousCuesSize; ++i) {
        // 10 - For each text track cue in other cues that has its text
        // track cue active flag set prepare an event named exit for the
        // TextTrackCue object with the text track cue end time.
        if (!currentCues.contains(previousCues[i]))
            eventTasks.append(std::make_pair(previousCues[i].data()->endTime(),
                                             previousCues[i].data()));
    }

    for (size_t i = 0; i < currentCuesSize; ++i) {
        // 11 - For each text track cue in current cues that does not have its
        // text track cue active flag set, prepare an event named enter for the
        // TextTrackCue object with the text track cue start time.
        if (!previousCues.contains(currentCues[i]))
            eventTasks.append(std::make_pair(currentCues[i].data()->startTime(),
                                             currentCues[i].data()));
    }

    // 12 - Sort the tasks in events in ascending time order (tasks with earlier
    // times first).
    nonCopyingSort(eventTasks.begin(), eventTasks.end(), eventTimeCueCompare);

    for (size_t i = 0; i < eventTasks.size(); ++i) {
        if (!affectedTracks.contains(eventTasks[i].second->track()))
            affectedTracks.append(eventTasks[i].second->track());

        // 13 - Queue each task in events, in list order.
        RefPtr<Event> event;

        // Each event in eventTasks may be either an enterEvent or an exitEvent,
        // depending on the time that is associated with the event. This
        // correctly identifies the type of the event, if the startTime is
        // less than the endTime in the cue.
        if (eventTasks[i].second->startTime() >= eventTasks[i].second->endTime()) {
            event = Event::create(eventNames().enterEvent, false, false);
            event->setTarget(eventTasks[i].second);
            m_asyncEventQueue->enqueueEvent(event.release());

            event = Event::create(eventNames().exitEvent, false, false);
            event->setTarget(eventTasks[i].second);
            m_asyncEventQueue->enqueueEvent(event.release());
        } else {
            if (eventTasks[i].first == eventTasks[i].second->startTime())
                event = Event::create(eventNames().enterEvent, false, false);
            else
                event = Event::create(eventNames().exitEvent, false, false);

            event->setTarget(eventTasks[i].second);
            m_asyncEventQueue->enqueueEvent(event.release());
        }
    }

    // 14 - Sort affected tracks in the same order as the text tracks appear in
    // the media element's list of text tracks, and remove duplicates.
    nonCopyingSort(affectedTracks.begin(), affectedTracks.end(), trackIndexCompare);

    // 15 - For each text track in affected tracks, in the list order, queue a
    // task to fire a simple event named cuechange at the TextTrack object, and, ...
    for (size_t i = 0; i < affectedTracks.size(); ++i) {
        RefPtr<Event> event = Event::create(eventNames().cuechangeEvent, false, false);
        event->setTarget(affectedTracks[i]);

        m_asyncEventQueue->enqueueEvent(event.release());

        // ... if the text track has a corresponding track element, to then fire a
        // simple event named cuechange at the track element as well.
        if (affectedTracks[i]->trackType() == TextTrack::TrackElement) {
            RefPtr<Event> event = Event::create(eventNames().cuechangeEvent, false, false);
            HTMLTrackElement* trackElement = static_cast<LoadableTextTrack*>(affectedTracks[i])->trackElement();
            ASSERT(trackElement);
            event->setTarget(trackElement);
            
            m_asyncEventQueue->enqueueEvent(event.release());
        }
    }

    // 16 - Set the text track cue active flag of all the cues in the current
    // cues, and unset the text track cue active flag of all the cues in the
    // other cues.
    for (size_t i = 0; i < currentCuesSize; ++i)
        currentCues[i].data()->setIsActive(true);

    for (size_t i = 0; i < previousCuesSize; ++i)
        if (!currentCues.contains(previousCues[i]))
            previousCues[i].data()->setIsActive(false);

    // Update the current active cues.
    m_currentlyActiveCues = currentCues;

    if (activeSetChanged)
        updateTextTrackDisplay();
}

bool HTMLMediaElement::textTracksAreReady() const
{
    // 4.8.10.12.1 Text track model
    // ...
    // The text tracks of a media element are ready if all the text tracks whose mode was not 
    // in the disabled state when the element's resource selection algorithm last started now
    // have a text track readiness state of loaded or failed to load.
    for (unsigned i = 0; i < m_textTracksWhenResourceSelectionBegan.size(); ++i) {
        if (m_textTracksWhenResourceSelectionBegan[i]->readinessState() == TextTrack::Loading
			|| m_textTracksWhenResourceSelectionBegan[i]->readinessState() == TextTrack::NotLoaded)
            return false;
    }

    return true;
}

void HTMLMediaElement::textTrackReadyStateChanged(TextTrack* track)
{
    gMediaLog("HTMLMediaElement(%p)::textTrackReadyStateChanged() readinessState %i\n", this, track->readinessState());

    if (m_player && m_textTracksWhenResourceSelectionBegan.contains(track)) {
        if (track->readinessState() != TextTrack::Loading)
            setReadyState(m_player->readyState());
    } else {
		// The track readiness state might have changed as a result of the user
		// clicking the captions button. In this case, a check whether all the
		// resources have failed loading should be done in order to hide the CC button.
		if (hasMediaControls() && track->readinessState() == TextTrack::FailedToLoad)
			mediaControls()->refreshClosedCaptionsButtonVisibility();
	}
}

void HTMLMediaElement::audioTrackEnabledChanged(AudioTrack* track)
{
    // We will want to change the media controls here once they exist

    gMediaLog("HTMLMediaElement(%p)::audioTrackEnabledChanged()\n", this);

    if(m_player)
    	m_player->audioTrackEnabledChanged(track, m_audioTracks.get());
}

void HTMLMediaElement::textTrackModeChanged(TextTrack* track)
{
    gMediaLog("HTMLMediaElement(%p)::textTrackModeChanged(%i)\n", this, track->trackType());

    if (track->trackType() == TextTrack::TrackElement) {
        // 4.8.10.12.3 Sourcing out-of-band text tracks
        // ... when a text track corresponding to a track element is created with text track
        // mode set to disabled and subsequently changes its text track mode to hidden, showing,
        // or showing by default for the first time, the user agent must immediately and synchronously
        // run the following algorithm ...

        for (Node* node = firstChild(); node; node = node->nextSibling()) {
            if (!node->hasTagName(trackTag))
                continue;
            HTMLTrackElement* trackElement = static_cast<HTMLTrackElement*>(node);
            if (trackElement->track() != track)
                continue;
            
            // Mark this track as "configured" so configureTextTracks won't change the mode again.
            track->setHasBeenConfigured(true);
            if (track->mode() != TextTrack::disabledKeyword()) {
                if (trackElement->readyState() == HTMLTrackElement::LOADED)
                    textTrackAddCues(track, track->cues());

                // If this is the first added track, create the list of text tracks.
                if (!m_textTracks)
                  m_textTracks = TextTrackList::create(this, ActiveDOMObject::scriptExecutionContext());
            }
            break;
        }
    }

    configureTextTrackDisplay();
}

void HTMLMediaElement::videoTrackSelectedChanged(VideoTrack*)
{
    // We will want to change the media controls here once they exist

    gMediaLog("HTMLMediaElement(%p)::videoTrackSelectedChanged()\n", this);
}

void HTMLMediaElement::textTrackKindChanged(TextTrack* track)
{
    gMediaLog("HTMLMediaElement(%p)::textTrackKindChanged(%s)\n", this, track->kind().string().latin1().data());

    if (track->kind() != TextTrack::captionsKeyword() && track->kind() != TextTrack::subtitlesKeyword() && track->mode() == TextTrack::showingKeyword())
        track->setMode(TextTrack::hiddenKeyword());
}

void HTMLMediaElement::textTrackAddCues(TextTrack*, const TextTrackCueList* cues) 
{
    gMediaLog("HTMLMediaElement(%p)::textTrackAddCues()\n", this);

    beginIgnoringTrackDisplayUpdateRequests();
    for (size_t i = 0; i < cues->length(); ++i)
        textTrackAddCue(cues->item(i)->track(), cues->item(i));
    endIgnoringTrackDisplayUpdateRequests();
    updateActiveTextTrackCues(currentTime());
}

void HTMLMediaElement::textTrackRemoveCues(TextTrack*, const TextTrackCueList* cues) 
{
    gMediaLog("HTMLMediaElement(%p)::textTrackRemoveCues()\n", this);

    beginIgnoringTrackDisplayUpdateRequests();
    for (size_t i = 0; i < cues->length(); ++i)
        textTrackRemoveCue(cues->item(i)->track(), cues->item(i));
    endIgnoringTrackDisplayUpdateRequests();
    updateActiveTextTrackCues(currentTime());
}

void HTMLMediaElement::textTrackAddCue(TextTrack*, PassRefPtr<TextTrackCue> cue)
{
    gMediaLog("HTMLMediaElement(%p)::textTrackAddCue(%f, %f)\n", this, cue->startTime(), cue->endTime());

    // Negative duration cues need be treated in the interval tree as
    // zero-length cues.
    double endTime = max(cue->startTime(), cue->endTime());

    CueIntervalTree::IntervalType interval = m_cueTree.createInterval(cue->startTime(), endTime, cue.get());
    if (!m_cueTree.contains(interval))
        m_cueTree.add(interval);
    updateActiveTextTrackCues(currentTime());
}

void HTMLMediaElement::textTrackRemoveCue(TextTrack*, PassRefPtr<TextTrackCue> cue)
{
    gMediaLog("HTMLMediaElement(%p)::textTrackRemoveCue()\n", this);

    // Negative duration cues need to be treated in the interval tree as
    // zero-length cues.
    double endTime = max(cue->startTime(), cue->endTime());

    CueInterval interval = m_cueTree.createInterval(cue->startTime(), endTime, cue.get());
    m_cueTree.remove(interval);

	size_t index = m_currentlyActiveCues.find(interval);
	if (index != notFound)
		m_currentlyActiveCues.remove(index);

    cue->removeDisplayTree();
    updateActiveTextTrackCues(currentTime());
}

#endif

bool HTMLMediaElement::isSafeToLoadURL(const KURL& url, InvalidURLAction actionIfInvalid)
{
    if (!url.isValid()) {
        gMediaLog("HTMLMediaElement(%p)::isSafeToLoadURL(%s) -> FALSE because url is invalid\n", this, urlForLogging(url).utf8().data());
        //return false;
    }

    Frame* frame = document().frame();

    if(!frame)
    	return false;

    if (!document().securityOrigin()->canDisplay(url) &&
    	!frame->loader()->client()->canDisplay(&document(), url))
    {
        if (actionIfInvalid == Complain)
            FrameLoader::reportLocalLoadFailed(frame, url.string());
        gMediaLog("HTMLMediaElement(%p)::isSafeToLoadURL(%s) -> FALSE rejected by SecurityOrigin\n", this, urlForLogging(url).utf8().data());
        return false;
    }

    if (!document().contentSecurityPolicy()->allowMediaFromSource(url, isInUserAgentShadowTree())) {
        gMediaLog("HTMLMediaElement(%p)::isSafeToLoadURL(%s) -> rejected by Content Security Policy\n", this, urlForLogging(url).utf8().data());
        return false;
    }

    return true;
}

void HTMLMediaElement::startProgressEventTimer()
{
    if (m_progressEventTimer.isActive())
        return;

    m_previousProgressTime = WTF::monotonicallyIncreasingTime();
    // 350ms is not magic, it is in the spec!
    m_progressEventTimer.startRepeating(0.350);
}

void HTMLMediaElement::waitForSourceChange()
{
    gMediaLog("HTMLMediaElement(%p)::waitForSourceChange\n", this);

    stopPeriodicTimers();
    m_loadState = WaitingForSource;

    // 6.17 - Waiting: Set the element's networkState attribute to the NETWORK_NO_SOURCE value
    m_networkState = NETWORK_NO_SOURCE;

    // 6.18 - Set the element's delaying-the-load-event flag to false. This stops delaying the load event.
    setShouldDelayLoadEvent(false);

    updateDisplayState();

    if (renderer())
        renderer()->updateFromElement();
}

void HTMLMediaElement::noneSupported()
{
    gMediaLog("HTMLMediaElement(%p)::noneSupported\n", this);

    stopPeriodicTimers();
    m_loadState = WaitingForSource;
    m_currentSourceNode = 0;

    // 4.8.10.5 
    // 6 - Reaching this step indicates that the media resource failed to load or that the given 
    // URL could not be resolved. In one atomic operation, run the following steps:

    // 6.1 - Set the error attribute to a new MediaError object whose code attribute is set to
    // MEDIA_ERR_SRC_NOT_SUPPORTED.
    m_error = MediaError::create(MediaError::MEDIA_ERR_SRC_NOT_SUPPORTED);

    // 6.2 - Forget the media element's media-resource-specific text tracks.

    // 6.3 - Set the element's networkState attribute to the NETWORK_NO_SOURCE value.
    m_networkState = NETWORK_NO_SOURCE;

    // 7 - Queue a task to fire a simple event named error at the media element.
    scheduleEvent(eventNames().errorEvent);

#if ENABLE(MEDIA_SOURCE)
    detachMediaSource();
#endif

    // 8 - Set the element's delaying-the-load-event flag to false. This stops delaying the load event.
    setShouldDelayLoadEvent(false);

    // 9 - Abort these steps. Until the load() method is invoked or the src attribute is changed, 
    // the element won't attempt to load another resource.

    updateDisplayState();

    if (renderer())
        renderer()->updateFromElement();
}

void HTMLMediaElement::mediaEngineError(PassRefPtr<MediaError> err)
{
    gMediaLog("HTMLMediaElement(%p)::mediaEngineError(%d)\n", this, static_cast<int>(err->code()));

    // 1 - The user agent should cancel the fetching process.
    stopPeriodicTimers();
    m_loadState = WaitingForSource;

    // 2 - Set the error attribute to a new MediaError object whose code attribute is 
    // set to MEDIA_ERR_NETWORK/MEDIA_ERR_DECODE.
    m_error = err;

    // 3 - Queue a task to fire a simple event named error at the media element.
    scheduleEvent(eventNames().errorEvent);

#if ENABLE(MEDIA_SOURCE)
    detachMediaSource();
#endif

    // 4 - Set the element's networkState attribute to the NETWORK_EMPTY value and queue a
    // task to fire a simple event called emptied at the element.
    m_networkState = NETWORK_EMPTY;
    scheduleEvent(eventNames().emptiedEvent);

    // 5 - Set the element's delaying-the-load-event flag to false. This stops delaying the load event.
    setShouldDelayLoadEvent(false);

    // 6 - Abort the overall resource selection algorithm.
    m_currentSourceNode = 0;
}

void HTMLMediaElement::cancelPendingEventsAndCallbacks()
{
    gMediaLog("HTMLMediaElement(%p)::cancelPendingEventsAndCallbacks\n", this);
    m_asyncEventQueue->cancelAllEvents();

    for (Node* node = firstChild(); node; node = node->nextSibling()) {
        if (node->hasTagName(sourceTag))
            static_cast<HTMLSourceElement*>(node)->cancelPendingErrorEvent();
    }
}

void HTMLMediaElement::mediaPlayerNetworkStateChanged(MediaPlayer*)
{
    beginProcessingMediaPlayerCallback();
    setNetworkState(m_player->networkState());
    endProcessingMediaPlayerCallback();
}

static String stringForNetworkState(MediaPlayer::NetworkState state)
{
    switch (state) {
    case MediaPlayer::Empty: return "Empty";
    case MediaPlayer::Idle: return "Idle";
    case MediaPlayer::Loading: return "Loading";
    case MediaPlayer::Loaded: return "Loaded";
    case MediaPlayer::FormatError: return "FormatError";
    case MediaPlayer::NetworkError: return "NetworkError";
    case MediaPlayer::DecodeError: return "DecodeError";
    default: return emptyString();
    }
}

void HTMLMediaElement::mediaLoadingFailed(MediaPlayer::NetworkState error)
{
    stopPeriodicTimers();
    
    // If we failed while trying to load a <source> element, the movie was never parsed, and there are more
    // <source> children, schedule the next one
    if (m_readyState < HAVE_METADATA && m_loadState == LoadingFromSourceElement) {
        
        if (m_currentSourceNode)
            m_currentSourceNode->scheduleErrorEvent();
        else
            gMediaLog("HTMLMediaElement(%p)::setNetworkState - error event not sent, <source> was removed\n", this);
        
        if (havePotentialSourceChild()) {
            gMediaLog("HTMLMediaElement(%p)::setNetworkState - scheduling next <source>\n", this);
            scheduleNextSourceChild();
        } else {
            gMediaLog("HTMLMediaElement(%p)::setNetworkState - no more <source> elements, waiting\n", this);
            waitForSourceChange();
        }
        
        return;
    }
    
    if (error == MediaPlayer::NetworkError && m_readyState >= HAVE_METADATA)
        mediaEngineError(MediaError::create(MediaError::MEDIA_ERR_NETWORK));
    else if (error == MediaPlayer::DecodeError)
        mediaEngineError(MediaError::create(MediaError::MEDIA_ERR_DECODE));
    else if ((error == MediaPlayer::FormatError || error == MediaPlayer::NetworkError) && m_loadState == LoadingFromSrcAttr)
        noneSupported();
    
    updateDisplayState();
    if (hasMediaControls()) {
        mediaControls()->reset();
        mediaControls()->reportedError();
    }

    if (document().settings().diagnosticLoggingEnabled())
        document().page()->chrome()->client()->logDiagnosticMessage(DiagnosticLoggingKeys::mediaLoadingFailedKey(), stringForNetworkState(error), DiagnosticLoggingKeys::failKey());
}

void HTMLMediaElement::setNetworkState(MediaPlayer::NetworkState state)
{
    gMediaLog("HTMLMediaElement(%p)::setNetworkState(%d) - current state is %d\n", this, static_cast<int>(state), static_cast<int>(m_networkState));

    if (state == MediaPlayer::Empty) {
        // Just update the cached state and leave, we can't do anything.
        m_networkState = NETWORK_EMPTY;
        return;
    }

    if (state == MediaPlayer::FormatError || state == MediaPlayer::NetworkError || state == MediaPlayer::DecodeError) {
        mediaLoadingFailed(state);
        return;
    }

    if (state == MediaPlayer::Idle) {
        if (m_networkState > NETWORK_IDLE) {
            changeNetworkStateFromLoadingToIdle();
            setShouldDelayLoadEvent(false);
        } else {
            m_networkState = NETWORK_IDLE;
        }
    }

    if (state == MediaPlayer::Loading) {
        if (m_networkState < NETWORK_LOADING || m_networkState == NETWORK_NO_SOURCE){
			if (!m_completelyLoaded)            
				scheduleEvent(eventNames().loadstartEvent);
            startProgressEventTimer();
        }

        m_networkState = NETWORK_LOADING;
    }

    if (state == MediaPlayer::Loaded) {
        if (m_networkState != NETWORK_IDLE)
            changeNetworkStateFromLoadingToIdle();
        m_completelyLoaded = true;
    }

    if (hasMediaControls())
        mediaControls()->updateStatusDisplay();
}

void HTMLMediaElement::changeNetworkStateFromLoadingToIdle()
{
    m_progressEventTimer.stop();
    if (hasMediaControls() && m_player->didLoadingProgress())
        mediaControls()->bufferingProgressed();

    // Schedule one last progress event so we guarantee that at least one is fired
    // for files that load very quickly.
    scheduleEvent(eventNames().progressEvent);
    scheduleEvent(eventNames().suspendEvent);
    m_networkState = NETWORK_IDLE;
}

void HTMLMediaElement::mediaPlayerReadyStateChanged(MediaPlayer*)
{
    beginProcessingMediaPlayerCallback();

    setReadyState(m_player->readyState());

    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::setReadyState(MediaPlayer::ReadyState state)
{
    // Set "wasPotentiallyPlaying" BEFORE updating m_readyState, potentiallyPlaying() uses it
    bool wasPotentiallyPlaying = potentiallyPlaying();

    ReadyState oldState = m_readyState;
    ReadyState newState = static_cast<ReadyState>(state);

#if ENABLE(VIDEO_TRACK)
    bool tracksAreReady = !RuntimeEnabledFeatures::webkitVideoTrackEnabled() || textTracksAreReady();

    if (newState == oldState && m_tracksAreReady == tracksAreReady)
        return;

    m_tracksAreReady = tracksAreReady;
#else
    if (newState == oldState)
        return;
    bool tracksAreReady = true;
#endif

    gMediaLog("HTMLMediaElement(%p)::setReadyState(%d) - current state is %d, tracksAreReady %i\n", this, state, m_readyState, tracksAreReady);

    if (tracksAreReady)
        m_readyState = newState;
    else {
        // If a media file has text tracks the readyState may not progress beyond HAVE_FUTURE_DATA until
        // the text tracks are ready, regardless of the state of the media file.
        if (newState <= HAVE_METADATA)
            m_readyState = newState;
        else
            m_readyState = HAVE_CURRENT_DATA;
    }
    
    if (oldState > m_readyStateMaximum)
        m_readyStateMaximum = oldState;

    if (m_networkState == NETWORK_EMPTY)
        return;

    if (m_seeking) {
        // 4.8.10.9, step 11
        if (wasPotentiallyPlaying && m_readyState < HAVE_FUTURE_DATA)
            scheduleEvent(eventNames().waitingEvent);

        // 4.8.10.10 step 14 & 15.
        if (m_readyState >= HAVE_CURRENT_DATA)
            finishSeek();
    } else {
        if (wasPotentiallyPlaying && m_readyState < HAVE_FUTURE_DATA) {
            // 4.8.10.8
            scheduleTimeupdateEvent(false);
            scheduleEvent(eventNames().waitingEvent);
        }
    }

    if (m_readyState >= HAVE_METADATA && oldState < HAVE_METADATA) {
        prepareMediaFragmentURI();
        scheduleEvent(eventNames().durationchangeEvent);
        scheduleEvent(eventNames().loadedmetadataEvent);
        if (hasMediaControls())
            mediaControls()->loadedMetadata();
        if (renderer())
            renderer()->updateFromElement();

        if (document().settings().diagnosticLoggingEnabled())
            document().page()->chrome()->client()->logDiagnosticMessage(DiagnosticLoggingKeys::mediaLoadedKey(), m_player->engineDescription(), DiagnosticLoggingKeys::noopKey());
    }

    bool shouldUpdateDisplayState = false;

    if (m_readyState >= HAVE_CURRENT_DATA && oldState < HAVE_CURRENT_DATA) {
        if (!m_haveFiredLoadedData) {
            m_haveFiredLoadedData = true;
            scheduleEvent(eventNames().loadeddataEvent);
            // FIXME: It's not clear that it's correct to skip these two operations just
            // because m_haveFiredLoadedData is already true. At one time we were skipping
            // the call to setShouldDelayLoadEvent, which was definitely incorrect.
            shouldUpdateDisplayState = true;
            applyMediaFragmentURI();
        }
        setShouldDelayLoadEvent(false);
    }

    bool isPotentiallyPlaying = potentiallyPlaying();
    if (m_readyState == HAVE_FUTURE_DATA && oldState <= HAVE_CURRENT_DATA && tracksAreReady) {
        scheduleEvent(eventNames().canplayEvent);
        if (isPotentiallyPlaying)
            scheduleEvent(eventNames().playingEvent);
        shouldUpdateDisplayState = true;
    }

    if (m_readyState == HAVE_ENOUGH_DATA && oldState < HAVE_ENOUGH_DATA && tracksAreReady) {
        if (oldState <= HAVE_CURRENT_DATA)
            scheduleEvent(eventNames().canplayEvent);

        scheduleEvent(eventNames().canplaythroughEvent);

        if (isPotentiallyPlaying && oldState <= HAVE_CURRENT_DATA)
            scheduleEvent(eventNames().playingEvent);

        if (m_autoplaying && m_paused && autoplay() && !document().isSandboxed(SandboxAutomaticFeatures) && !userGestureRequiredForRateChange()) {
            m_paused = false;
            invalidateCachedTime();
            scheduleEvent(eventNames().playEvent);
            scheduleEvent(eventNames().playingEvent);
        }
        else {
            gMediaLog("  >m_autoplaying %i m_paused %i autoplay %i isSandboxed %i userGestureRequiredForRateChange %i\n",
            	m_autoplaying, m_paused, autoplay(), document().isSandboxed(SandboxAutomaticFeatures), userGestureRequiredForRateChange());
        }

        shouldUpdateDisplayState = true;
    }

    if (shouldUpdateDisplayState) {
        updateDisplayState();
        if (hasMediaControls()) {
            mediaControls()->refreshClosedCaptionsButtonVisibility();
            mediaControls()->updateStatusDisplay();
        }
    }

    updatePlayState();
    updateMediaController();
#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        updateActiveTextTrackCues(currentTime());
#endif
}

#if ENABLE(LEGACY_ENCRYPTED_MEDIA)
void HTMLMediaElement::mediaPlayerKeyAdded(MediaPlayer*, const String& keySystem, const String& sessionId)
{
    if (hasEventListeners(eventNames().keyaddedEvent)) {
    	RefPtr<Event> event = MediaKeyEvent::create(eventNames().keyaddedEvent, keySystem, sessionId, nullptr, nullptr, emptyString(), nullptr, 0);
    	event->setTarget(this);
    	m_asyncEventQueue->enqueueEvent(event.release());
    }
    else if (hasEventListeners(eventNames().webkitkeyaddedEvent)){
        RefPtr<Event> event = MediaKeyEvent::create(eventNames().webkitkeyaddedEvent, keySystem, sessionId, nullptr, nullptr, emptyString(), nullptr, 0);
        event->setTarget(this);
        m_asyncEventQueue->enqueueEvent(event.release());
    }
}

void HTMLMediaElement::mediaPlayerKeyError(MediaPlayer*, const String& keySystem, const String& sessionId, MediaPlayerClient::MediaKeyErrorCode errorCode, unsigned short systemCode)
{
	WebKitMediaKeyError::Code mediaKeyErrorCode = WebKitMediaKeyError::MEDIA_KEYERR_UNKNOWN;
    switch (errorCode) {
    case MediaPlayerClient::UnknownError:
        mediaKeyErrorCode = WebKitMediaKeyError::MEDIA_KEYERR_UNKNOWN;
        break;
    case MediaPlayerClient::ClientError:
        mediaKeyErrorCode = WebKitMediaKeyError::MEDIA_KEYERR_CLIENT;
        break;
    case MediaPlayerClient::ServiceError:
        mediaKeyErrorCode = WebKitMediaKeyError::MEDIA_KEYERR_SERVICE;
        break;
    case MediaPlayerClient::OutputError:
        mediaKeyErrorCode = WebKitMediaKeyError::MEDIA_KEYERR_OUTPUT;
        break;
    case MediaPlayerClient::HardwareChangeError:
        mediaKeyErrorCode = WebKitMediaKeyError::MEDIA_KEYERR_HARDWARECHANGE;
        break;
    case MediaPlayerClient::DomainError:
        mediaKeyErrorCode = WebKitMediaKeyError::MEDIA_KEYERR_DOMAIN;
        break;
    }

    if (hasEventListeners(eventNames().keyerrorEvent)) {
    	RefPtr<Event> event = MediaKeyEvent::create(eventNames().keyerrorEvent, keySystem, sessionId, nullptr, nullptr, emptyString(), WebKitMediaKeyError::create(mediaKeyErrorCode), systemCode);
    	event->setTarget(this);
    	m_asyncEventQueue->enqueueEvent(event.release());
    }
    else if (hasEventListeners(eventNames().webkitkeyerrorEvent)) {
        RefPtr<Event> event = MediaKeyEvent::create(eventNames().webkitkeyerrorEvent, keySystem, sessionId, nullptr, nullptr, emptyString(), WebKitMediaKeyError::create(mediaKeyErrorCode), systemCode);
        event->setTarget(this);
        m_asyncEventQueue->enqueueEvent(event.release());
    }
}

void HTMLMediaElement::mediaPlayerKeyMessage(MediaPlayer*, const String& keySystem, const String& sessionId, const unsigned char* message, unsigned messageLength)
{
    if (hasEventListeners(eventNames().keymessageEvent)) {
    	RefPtr<Event> event = MediaKeyEvent::create(eventNames().keymessageEvent, keySystem, sessionId, nullptr, Uint8Array::create(message, messageLength), emptyString(), nullptr, 0);
    	event->setTarget(this);
    	m_asyncEventQueue->enqueueEvent(event.release());
    	return;
    }

    if (hasEventListeners(eventNames().webkitkeymessageEvent)){
        RefPtr<Event> event = MediaKeyEvent::create(eventNames().webkitkeymessageEvent, keySystem, sessionId, nullptr, Uint8Array::create(message, messageLength), emptyString(), nullptr, 0);
        event->setTarget(this);
        m_asyncEventQueue->enqueueEvent(event.release());
        return;
    }

#if ENABLE(ENCRYPTED_MEDIA)
    if(m_mediaKeys) {
    	m_mediaKeys->cdmInstance()->keyMessage(keySystem, sessionId, message, messageLength);
		return;
    }
#endif

    gMediaLog("HTMLMediaElement(%p)::mediaPlayerKeyMessage(%s, %s) - no event listener\n", this, keySystem.utf8().data(), sessionId.utf8().data());
}

void HTMLMediaElement::mediaPlayerKeyNeeded(MediaPlayer*, const String& keySystem, const String& sessionId, const unsigned char* initData, unsigned initDataLength, const String& initDataType)
{
#if ENABLE(ENCRYPTED_MEDIA)
    if (hasEventListeners(eventNames().encryptedEvent)){
		RefPtr<Event> event = MediaEncryptedEvent::create(eventNames().encryptedEvent, initDataType, JSC::ArrayBuffer::tryCreate(initData, initDataLength));
		event->setTarget(this);
		m_asyncEventQueue->enqueueEvent(event.release());
		return;
    }
#endif

    if (hasEventListeners(eventNames().needkeyEvent)) {
		RefPtr<Event> event = MediaKeyEvent::create(eventNames().needkeyEvent, keySystem, sessionId, Uint8Array::create(initData, initDataLength), nullptr, emptyString(), nullptr, 0);
		event->setTarget(this);
		m_asyncEventQueue->enqueueEvent(event.release());
    }
    else if (hasEventListeners(eventNames().webkitneedkeyEvent)){
		RefPtr<Event> event = MediaKeyEvent::create(eventNames().webkitneedkeyEvent, keySystem, sessionId, Uint8Array::create(initData, initDataLength), nullptr, emptyString(), nullptr, 0);
		event->setTarget(this);
		m_asyncEventQueue->enqueueEvent(event.release());
    }
    else{
        m_error = MediaError::create(MediaError::MEDIA_ERR_ENCRYPTED);
        scheduleEvent(eventNames().errorEvent);
    }
}
#endif

#if ENABLE(LEGACY_ENCRYPTED_MEDIA_V2)
void HTMLMediaElement::mediaPlayerKeyNeeded(MediaPlayer*, Uint8Array* initData, const String& initDataType)
{
#if ENABLE(ENCRYPTED_MEDIA)
    if (hasEventListeners(eventNames().encryptedEvent)){
		RefPtr<Event> event = MediaEncryptedEvent::create(eventNames().encryptedEvent, initDataType, initData->buffer());
		event->setTarget(this);
		m_asyncEventQueue->enqueueEvent(event.release());
		return;
    }
#endif

    if (hasEventListeners(eventNames().needkeyEvent)) {
        RefPtr<Event> event = WebKitMediaKeyNeededEvent::create(eventNames().needkeyEvent, initData);
        event->setTarget(this);
        m_asyncEventQueue->enqueueEvent(event.release());
    }
    else if (hasEventListeners(eventNames().webkitneedkeyEvent)) {
		RefPtr<Event> event = WebKitMediaKeyNeededEvent::create(eventNames().webkitneedkeyEvent, initData);
		event->setTarget(this);
		m_asyncEventQueue->enqueueEvent(event.release());
    }
    else{
        m_error = MediaError::create(MediaError::MEDIA_ERR_ENCRYPTED);
        scheduleEvent(eventNames().errorEvent);
    }
}

void HTMLMediaElement::webkitSetMediaKeys(WebKitMediaKeys* mediaKeys)
{
    gMediaLog("HTMLMediaElement(%p)::webkitSetMediaKeys\n", this);

    if (m_webKitMediaKeys == mediaKeys)
        return;

    if (m_webKitMediaKeys)
        m_webKitMediaKeys->setMediaElement(0);
    m_webKitMediaKeys = mediaKeys;
    if (m_webKitMediaKeys)
        m_webKitMediaKeys->setMediaElement(this);
}
#endif

#if ENABLE(ENCRYPTED_MEDIA)

namespace
{

class SetMediaKeysTask : public GenericTask<HTMLMediaElement>
{
public:
	SetMediaKeysTask(HTMLMediaElement* mediaElement, HTMLMediaElement::PromiseVoid promise)
	: GenericTask<HTMLMediaElement>(makeWeakPtr(*mediaElement))
	, promise(promise)
    {
    }

	virtual ~SetMediaKeysTask()
	{
	}

	virtual void exec()
	{
		if(!weakThis)
			return;

		promise.resolve(std::nullptr_t());
	}

private:
	HTMLMediaElement::PromiseVoid promise;
};

}

void HTMLMediaElement::setMediaKeys(MediaKeys* mediaKeys, PromiseVoid promise)
{
    gMediaLog("HTMLMediaElement(%p)::setMediaKeys\n", this);

	m_mediaKeys = mediaKeys;

	if(m_player) {
		if(m_mediaKeys)
			m_player->attachMediaKeys(m_mediaKeys.get());
	}

	m_taskQueue.enqueueTask(adoptPtr(new SetMediaKeysTask(this, promise)));
}

#endif // ENABLE(ENCRYPTED_MEDIA)

void HTMLMediaElement::progressEventTimerFired()
{
    ASSERT(m_player);
    if (m_networkState != NETWORK_LOADING)
        return;

    double time = WTF::monotonicallyIncreasingTime();
    double timedelta = time - m_previousProgressTime;

    if (m_player->didLoadingProgress()) {
        scheduleEvent(eventNames().progressEvent);
        m_previousProgressTime = time;
        m_sentStalledEvent = false;
        if (renderer())
            renderer()->updateFromElement();
        if (hasMediaControls())
            mediaControls()->bufferingProgressed();
    } else if (timedelta > 3.0 && !m_sentStalledEvent) {
        scheduleEvent(eventNames().stalledEvent);
        m_sentStalledEvent = true;
        setShouldDelayLoadEvent(false);
    }
}

void HTMLMediaElement::rewind(double timeDelta)
{
    gMediaLog("HTMLMediaElement(%p)::rewind(%f)\n", this, timeDelta);
    setCurrentTime(std::max(currentMediaTime() - MediaTime::createWithDouble(timeDelta), minTimeSeekable()));
}

void HTMLMediaElement::returnToRealtime()
{
    gMediaLog("HTMLMediaElement(%p)::returnToRealtime\n", this);
    setCurrentTime(maxTimeSeekable());
}  

void HTMLMediaElement::addPlayedRange(const MediaTime& start, const MediaTime& end)
{
    //LOG(Media, "HTMLMediaElement::addPlayedRange(%s, %s)", toString(start).utf8().data(), toString(end).utf8().data());
    if (!m_playedTimeRanges)
        m_playedTimeRanges = TimeRanges::create();
    m_playedTimeRanges->ranges().add(start, end);
}  

bool HTMLMediaElement::supportsSave() const
{
    return m_player ? m_player->supportsSave() : false;
}

bool HTMLMediaElement::supportsScanning() const
{
    return m_player ? m_player->supportsScanning() : false;
}

void HTMLMediaElement::prepareToPlay()
{
    gMediaLog("HTMLMediaElement(%p)::prepareToPlay()\n", this);
    if (m_havePreparedToPlay || !document().hasBrowsingContext())
        return;
    m_havePreparedToPlay = true;
    if(m_player)
    	m_player->prepareToPlay();
}

void HTMLMediaElement::fastSeek(double time)
{
    fastSeek(MediaTime::createWithDouble(time));
}

void HTMLMediaElement::fastSeek(const MediaTime& time)
{
    LOG(Media, "HTMLMediaElement::fastSeek(%s)", toString(time).utf8().data());
    // 4.7.10.9 Seeking
    // 9. If the approximate-for-speed flag is set, adjust the new playback position to a value that will
    // allow for playback to resume promptly. If new playback position before this step is before current
    // playback position, then the adjusted new playback position must also be before the current playback
    // position. Similarly, if the new playback position before this step is after current playback position,
    // then the adjusted new playback position must also be after the current playback position.
    refreshCachedTime();
    MediaTime delta = time - currentMediaTime();
    MediaTime negativeTolerance = delta >= MediaTime::zeroTime() ? delta : MediaTime::positiveInfiniteTime();
    MediaTime positiveTolerance = delta < MediaTime::zeroTime() ? -delta : MediaTime::positiveInfiniteTime();

    seekWithTolerance(time, negativeTolerance, positiveTolerance, true);
}

void HTMLMediaElement::seek(const MediaTime& time)
{
    LOG(Media, "HTMLMediaElement::seek(%s)", toString(time).utf8().data());
    seekWithTolerance(time, MediaTime::zeroTime(), MediaTime::zeroTime(), true);
}

bool HTMLMediaElement::seekInternal(const MediaTime& time)
{
    LOG(Media, "HTMLMediaElement::seekInternal(%s)", toString(time).utf8().data());
    return seekWithTolerance(time, MediaTime::zeroTime(), MediaTime::zeroTime(), false);
}

bool HTMLMediaElement::seekWithTolerance(const MediaTime& inTime, const MediaTime& negativeTolerance, const MediaTime& positiveTolerance, bool fromDOM)
{
    // 4.8.10.9 Seeking
    MediaTime time = inTime;

    gMediaLog("HTMLMediaElement(%p)::seekWithTolerance(%s) m_readyState %i m_player %p\n", this, toString(time).utf8().data(), m_readyState, m_player.get());

	// 1 - Set the media element's show poster flag to false.
	setDisplayMode(Video);

	// 2 - If the media element's readyState is HAVE_NOTHING, abort these steps.
	if (m_readyState == HAVE_NOTHING || !m_player)
		return false;

    // If the media engine has been told to postpone loading data, let it go ahead now.
    if (m_preload < MediaPlayer::Auto && m_readyState < HAVE_FUTURE_DATA)
        prepareToPlay();

    // Get the current time before setting m_seeking, m_lastSeekTime is returned once it is set.
    refreshCachedTime();
    MediaTime now = currentMediaTime();

    // 3 - If the element's seeking IDL attribute is true, then another instance of this algorithm is
    // already running. Abort that other instance of the algorithm without waiting for the step that
    // it is running to complete.
    if (m_seeking) {
        m_seekTimer.stop();
        m_pendingSeek = nullptr;
    }

    // 4 - Set the seeking IDL attribute to true.
    // The flag will be cleared when the engine tells us the time has actually changed.
    m_seeking = true;
    if (m_playing) {
        if (m_lastSeekTime < now)
            addPlayedRange(m_lastSeekTime, now);
    }
    m_lastSeekTime = time;

    // 5 - If the seek was in response to a DOM method call or setting of an IDL attribute, then continue
    // the script. The remainder of these steps must be run asynchronously.
    m_pendingSeek = adoptPtr(new PendingSeek(now, time, negativeTolerance, positiveTolerance));
    if (fromDOM)
        m_seekTimer.startOneShot(0);
    else
        return seekTimerFiredInternal();

    return true;
}

bool HTMLMediaElement::seekTimerFiredInternal()
{
    if (!m_player) {
        m_seeking = false;
        return true;
    }

    ASSERT(m_pendingSeek);
    MediaTime now = m_pendingSeek->now;
    MediaTime time = m_pendingSeek->targetTime;
    MediaTime negativeTolerance = m_pendingSeek->negativeTolerance;
    MediaTime positiveTolerance = m_pendingSeek->positiveTolerance;
    m_pendingSeek = nullptr;

    // 6 - If the new playback position is later than the end of the media resource, then let it be the end
    // of the media resource instead.
    MediaTime dur = durationMediaTime();
    if(dur.isValid())
    	time = std::min(time, dur);

    // 7 - If the new playback position is less than the earliest possible position, let it be that position instead.
    MediaTime earliestTime = m_player->startTime();
    time = max(time, earliestTime);

    // Ask the media engine for the time value in the movie's time scale before comparing with current time. This
    // is necessary because if the seek time is not equal to currentTime but the delta is less than the movie's
    // time scale, we will ask the media engine to "seek" to the current movie time, which may be a noop and
    // not generate a timechanged callback. This means m_seeking will never be cleared and we will never 
    // fire a 'seeked' event.
#if !LOG_DISABLED
    MediaTime mediaTime = m_player->mediaTimeForTimeValue(time);
    if (time != mediaTime)
        LOG(Media, "HTMLMediaElement::seekTimerFired(%s) - media timeline equivalent is %s", toString(time).utf8().data(), toString(mediaTime).utf8().data());
#endif
    time = m_player->mediaTimeForTimeValue(time);

    // 8 - If the (possibly now changed) new playback position is not in one of the ranges given in the
    // seekable attribute, then let it be the position in one of the ranges given in the seekable attribute 
    // that is the nearest to the new playback position. ... If there are no ranges given in the seekable
    // attribute then set the seeking IDL attribute to false and abort these steps.
    RefPtr<TimeRanges> seekableRanges = seekable();

    // Short circuit seeking to the current time by just firing the events if no seek is required.
    // Don't skip calling the media engine if we are in poster mode because a seek should always 
    // cancel poster display.
    bool noSeekRequired = !seekableRanges->length() || (time == now && displayMode() != Poster);

#if ENABLE(MEDIA_SOURCE)
    // Always notify the media engine of a seek if the source is not closed. This ensures that the source is
    // always in a flushed state when the 'seeking' event fires.
    if (m_mediaSource && !m_mediaSource->isClosed())
        noSeekRequired = false;
#endif

    if (noSeekRequired) {
        if (time == now) {
            scheduleEvent(eventNames().seekingEvent);
            scheduleTimeupdateEvent(false);
            scheduleEvent(eventNames().seekedEvent);
        }
        m_seeking = false;
        gMediaLog("HTMLMediaElement(%p)::seekTimerFiredInternal(%s) no seek required.\n", this, toString(time).utf8().data());
        return false;
    }

    time = seekableRanges->ranges().nearest(time);

    m_sentEndEvent = false;
    m_lastSeekTime = time;

    // 10 - Queue a task to fire a simple event named seeking at the element.
    scheduleEvent(eventNames().seekingEvent);

    // 11 - Set the current playback position to the given new playback position
    bool result = m_player->seekWithTolerance(time, negativeTolerance, positiveTolerance);

    // 12 - Wait until the user agent has established whether or not the media data for the new playback
    // position is available, and, if it is, until it has decoded enough data to play back that position.
    // 13 - Await a stable state. The synchronous section consists of all the remaining steps of this algorithm.

    return result;
}

void HTMLMediaElement::seekTimerFired()
{
	seekTimerFiredInternal();
}

void HTMLMediaElement::uncheckedSeek(double time)
{
	uncheckedSeek(MediaTime::createWithDouble(time));
}

void HTMLMediaElement::uncheckedSeek(MediaTime time)
{
    gMediaLog("HTMLMediaElement(%p)::uncheckedSeek(%s)\n", this, toString(time).utf8().data());

	// 4.8.10.9 Seeking

	// 1 - Set the media element's show poster flag to false.
	setDisplayMode(Video);

	// 2 - If the media element's readyState is HAVE_NOTHING, abort these steps.
	if (!m_player)
		return;

    // If the media engine has been told to postpone loading data, let it go ahead now.
    if (m_preload < MediaPlayer::Auto && m_readyState < HAVE_FUTURE_DATA)
        prepareToPlay();

    // Get the current time before setting m_seeking, m_lastSeekTime is returned once it is set.
    refreshCachedTime();
    MediaTime now = currentMediaTime();

    // 3 - If the element's seeking IDL attribute is true, then another instance of this algorithm is
    // already running. Abort that other instance of the algorithm without waiting for the step that
    // it is running to complete.
    // Nothing specific to be done here.

    // 4 - Set the seeking IDL attribute to true.
    // The flag will be cleared when the engine tells us the time has actually changed.
    m_seeking = true;

    // 5 - If the seek was in response to a DOM method call or setting of an IDL attribute, then continue
    // the script. The remainder of these steps must be run asynchronously.
    // Nothing to be done here.

    // 6 - If the new playback position is later than the end of the media resource, then let it be the end
    // of the media resource instead.

    // 7 - If the new playback position is less than the earliest possible position, let it be that position instead.

    // Ask the media engine for the time value in the movie's time scale before comparing with current time. This
    // is necessary because if the seek time is not equal to currentTime but the delta is less than the movie's
    // time scale, we will ask the media engine to "seek" to the current movie time, which may be a noop and
    // not generate a timechanged callback. This means m_seeking will never be cleared and we will never
    // fire a 'seeked' event.
#if !LOG_DISABLED
    double mediaTime = m_player->mediaTimeForTimeValue(time);
    if (time != mediaTime)
        gMediaLog("HTMLMediaElement(%p)::uncheckedSeek(%f) - media timeline equivalent is %f\n", this, time, mediaTime);
#endif
    time = m_player->mediaTimeForTimeValue(time);

    // 8 - If the (possibly now changed) new playback position is not in one of the ranges given in the
    // seekable attribute, then let it be the position in one of the ranges given in the seekable attribute
    // that is the nearest to the new playback position. ... If there are no ranges given in the seekable
    // attribute then set the seeking IDL attribute to false and abort these steps.

    if (m_playing) {
        if (m_lastSeekTime < now)
            addPlayedRange(m_lastSeekTime, now);
    }
    m_lastSeekTime = time;
    m_sentEndEvent = false;

    // 10 - Queue a task to fire a simple event named seeking at the element.
    scheduleEvent(eventNames().seekingEvent);

    // 11 - Set the current playback position to the given new playback position
    m_player->seekWithTolerance(time, MediaTime::zeroTime(), MediaTime::zeroTime());

    // 12 - Wait until the user agent has established whether or not the media data for the new playback
    // position is available, and, if it is, until it has decoded enough data to play back that position.
    // 13 - Await a stable state. The synchronous section consists of all the remaining steps of this algorithm.
}

void HTMLMediaElement::finishSeek()
{
    gMediaLog("HTMLMediaElement(%p)::finishSeek\n", this);

    // 4.8.10.9 Seeking
    // 14 - Set the seeking IDL attribute to false.
    m_seeking = false;

    // 15 - Run the time maches on steps.
    // Handled by mediaPlayerTimeChanged().

    // 16 - Queue a task to fire a simple event named timeupdate at the element.
    scheduleEvent(eventNames().timeupdateEvent);

    // 17 - Queue a task to fire a simple event named seeked at the element.
    scheduleEvent(eventNames().seekedEvent);
}

HTMLMediaElement::ReadyState HTMLMediaElement::readyState() const
{
    return m_readyState;
}

MediaPlayer::MovieLoadType HTMLMediaElement::movieLoadType() const
{
    return m_player ? m_player->movieLoadType() : MediaPlayer::Unknown;
}

bool HTMLMediaElement::hasAudio() const
{
    return m_player ? m_player->hasAudio() : false;
}

bool HTMLMediaElement::seeking() const
{
    return m_seeking;
}

void HTMLMediaElement::refreshCachedTime() const
{
    m_cachedTime = m_player->currentTime();
    m_clockTimeAtLastCachedTimeUpdate = monotonicallyIncreasingTime();
}

void HTMLMediaElement::invalidateCachedTime()
{
#if !LOG_DISABLED
    if (m_cachedTime.isValid())
        LOG(Media, "HTMLMediaElement::invalidateCachedTime");
#endif

    // Don't try to cache movie time when playback first starts as the time reported by the engine
    // sometimes fluctuates for a short amount of time, so the cached time will be off if we take it
    // too early.
    static const double minimumTimePlayingBeforeCacheSnapshot = 0.5;

    m_minimumClockTimeToUpdateCachedTime = monotonicallyIncreasingTime() + minimumTimePlayingBeforeCacheSnapshot;
    m_cachedTime = MediaTime::invalidTime();
}

// playback state
double HTMLMediaElement::currentTime() const
{
    return currentMediaTime().toDouble();
}

MediaTime HTMLMediaElement::currentMediaTime() const
{
#if LOG_CACHED_TIME_WARNINGS
    static const MediaTime minCachedDeltaForWarning = MediaTime::create(1, 100);
#endif

    if (!m_player)
        return MediaTime::zeroTime();

    if (m_seeking) {
        gMediaLog("HTMLMediaElement(%p)::currentTime - seeking, returning %s\n", this, toString(m_lastSeekTime).utf8().data());
        return m_lastSeekTime;
    }

    if (m_cachedTime.isValid() && m_paused) {
#if LOG_CACHED_TIME_WARNINGS
        MediaTime delta = m_cachedTime - m_player->currentTime();
        if (delta > minCachedDeltaForWarning)
            LOG(Media, "HTMLMediaElement::currentTime - WARNING, cached time is %s seconds off of media time when paused", toString(delta).utf8().data());
#endif
        return m_cachedTime;
    }

    // Is it too soon use a cached time?
    double now = monotonicallyIncreasingTime();
    double maximumDurationToCacheMediaTime = m_player->maximumDurationToCacheMediaTime();

    if (maximumDurationToCacheMediaTime && m_cachedTime.isValid() && !m_paused && now > m_minimumClockTimeToUpdateCachedTime) {
        double clockDelta = now - m_clockTimeAtLastCachedTimeUpdate;

        // Not too soon, use the cached time only if it hasn't expired.
        if (clockDelta < maximumDurationToCacheMediaTime) {
            MediaTime adjustedCacheTime = m_cachedTime + MediaTime::createWithDouble(effectivePlaybackRate() * clockDelta);

#if LOG_CACHED_TIME_WARNINGS
            MediaTime delta = adjustedCacheTime - m_player->currentTime();
            if (delta > minCachedDeltaForWarning)
                LOG(Media, "HTMLMediaElement::currentTime - WARNING, cached time is %f seconds off of media time when playing", delta);
#endif
            return adjustedCacheTime;
        }
    }

#if LOG_CACHED_TIME_WARNINGS
    if (maximumDurationToCacheMediaTime && now > m_minimumClockTimeToUpdateCachedTime && m_cachedTime.isValid()) {
        double clockDelta = now - m_clockTimeAtLastCachedTimeUpdate;
        MediaTime delta = m_cachedTime + MediaTime::createWithDouble(effectivePlaybackRate() * clockDelta) - m_player->currentTime();
        LOG(Media, "HTMLMediaElement::currentTime - cached time was %s seconds off of media time when it expired", toString(delta).utf8().data());
    }
#endif

    refreshCachedTime();

    if (m_cachedTime.isInvalid())
        return MediaTime::zeroTime();

    return m_cachedTime;
}

void HTMLMediaElement::setCurrentTime(double time)
{
    setCurrentTime(MediaTime::createWithDouble(time));
}

void HTMLMediaElement::setCurrentTime(const MediaTime& time)
{
    if (m_mediaController)
        return;

    seekInternal(time);
}

void HTMLMediaElement::setCurrentTime(double time, ExceptionCode& ec)
{
    // On setting, if the media element has a current media controller, then the user agent must
    // throw an InvalidStateError exception
    if (m_mediaController) {
        ec = INVALID_STATE_ERR;
        return;
    }

    seek(MediaTime::createWithDouble(time));
}

double HTMLMediaElement::duration() const
{
    return durationMediaTime().toDouble();
}

MediaTime HTMLMediaElement::durationMediaTime() const
{
    if (m_player)
        return m_player->duration();

    return MediaTime::invalidTime();
}

bool HTMLMediaElement::paused() const
{
    return m_paused;
}

double HTMLMediaElement::defaultPlaybackRate() const
{
#if ENABLE(MEDIA_STREAM)
    // http://w3c.github.io/mediacapture-main/#mediastreams-in-media-elements
    // "defaultPlaybackRate" - On setting: ignored. On getting: return 1.0
    // A MediaStream is not seekable. Therefore, this attribute must always have the
    // value 1.0 and any attempt to alter it must be ignored. Note that this also means
    // that the ratechange event will not fire.
    if (m_mediaStreamSrcObject)
        return 1;
#endif

    return m_defaultPlaybackRate;
}

void HTMLMediaElement::setDefaultPlaybackRate(double rate)
{
#if ENABLE(MEDIA_STREAM)
    // http://w3c.github.io/mediacapture-main/#mediastreams-in-media-elements
    // "defaultPlaybackRate" - On setting: ignored. On getting: return 1.0
    // A MediaStream is not seekable. Therefore, this attribute must always have the
    // value 1.0 and any attempt to alter it must be ignored. Note that this also means
    // that the ratechange event will not fire.
    if (m_mediaStreamSrcObject)
        return;
#endif

    if (m_defaultPlaybackRate != rate) {
        m_defaultPlaybackRate = rate;
        scheduleEvent(eventNames().ratechangeEvent);
    }
}

double HTMLMediaElement::effectivePlaybackRate() const
{
    return m_mediaController ? m_mediaController->playbackRate() : m_playbackRate;
}

double HTMLMediaElement::playbackRate() const
{
#if ENABLE(MEDIA_STREAM)
    // http://w3c.github.io/mediacapture-main/#mediastreams-in-media-elements
    // "playbackRate" - A MediaStream is not seekable. Therefore, this attribute must always
    // have the value 1.0 and any attempt to alter it must be ignored. Note that this also
    // means that the ratechange event will not fire.
    if (m_mediaStreamSrcObject)
        return 1;
#endif

    return m_playbackRate;
}

void HTMLMediaElement::setPlaybackRate(double rate)
{
    gMediaLog("HTMLMediaElement(%p)::setPlaybackRate(%f)\n", this, rate);

#if ENABLE(MEDIA_STREAM)
    // http://w3c.github.io/mediacapture-main/#mediastreams-in-media-elements
    // "playbackRate" - A MediaStream is not seekable. Therefore, this attribute must always
    // have the value 1.0 and any attempt to alter it must be ignored. Note that this also
    // means that the ratechange event will not fire.
    if (m_mediaStreamSrcObject)
        return;
#endif
    
    if (m_playbackRate != rate) {
        m_playbackRate = rate;
        invalidateCachedTime();
        scheduleEvent(eventNames().ratechangeEvent);
    }

    if (m_player && potentiallyPlaying() && !m_mediaController)
        m_player->setRate(rate);
}

void HTMLMediaElement::updatePlaybackRate()
{
    double effectiveRate = effectivePlaybackRate();
    if (m_player && potentiallyPlaying() && m_player->rate() != effectiveRate)
        m_player->setRate(effectiveRate);
}

bool HTMLMediaElement::webkitPreservesPitch() const
{
    return m_webkitPreservesPitch;
}

void HTMLMediaElement::setWebkitPreservesPitch(bool preservesPitch)
{
    gMediaLog("HTMLMediaElement(%p)::setWebkitPreservesPitch(%s)\n", this, boolString(preservesPitch));

    m_webkitPreservesPitch = preservesPitch;
    
    if (!m_player)
        return;

    m_player->setPreservesPitch(preservesPitch);
}

bool HTMLMediaElement::ended() const
{
#if ENABLE(MEDIA_STREAM)
    // http://w3c.github.io/mediacapture-main/#mediastreams-in-media-elements
    // When the MediaStream state moves from the active to the inactive state, the User Agent
    // must raise an ended event on the HTMLMediaElement and set its ended attribute to true.
    if (m_mediaStreamSrcObject && m_player && m_player->ended())
        return true;
#endif

    // 4.8.10.8 Playing the media resource
    // The ended attribute must return true if the media element has ended 
    // playback and the direction of playback is forwards, and false otherwise.
    return endedPlayback() && effectivePlaybackRate() > 0;
}

bool HTMLMediaElement::autoplay() const
{
    return hasAttributeWithoutSynchronization(autoplayAttr);
}

void HTMLMediaElement::setAutoplay(bool b)
{
    gMediaLog("HTMLMediaElement(%p)::setAutoplay(%s)\n", this, boolString(b));
    setBooleanAttribute(autoplayAttr, b);
}

String HTMLMediaElement::preload() const
{
#if ENABLE(MEDIA_STREAM)
    // http://w3c.github.io/mediacapture-main/#mediastreams-in-media-elements
    // "preload" - On getting: none. On setting: ignored.
    if (m_mediaStreamSrcObject)
        return ASCIILiteral("none");
#endif

    switch (m_preload) {
    case MediaPlayer::None:
        return "none";
        break;
    case MediaPlayer::MetaData:
        return "metadata";
        break;
    case MediaPlayer::Auto:
        return "auto";
        break;
    }

    ASSERT_NOT_REACHED();
    return String();
}

void HTMLMediaElement::setPreload(const String& preload)
{
    gMediaLog("HTMLMediaElement(%p)::setPreload(%s)\n", this, preload.utf8().data());
#if ENABLE(MEDIA_STREAM)
    // http://w3c.github.io/mediacapture-main/#mediastreams-in-media-elements
    // "preload" - On getting: none. On setting: ignored.
    if (m_mediaStreamSrcObject)
        return;
#endif

    setAttribute(preloadAttr, preload);
}

void HTMLMediaElement::play()
{
    gMediaLog("HTMLMediaElement(%p)::play() at %f\n", this, WTF::currentTime());

    if (userGestureRequiredForRateChange() && !ScriptController::processingUserGesture())
        return;
    if (ScriptController::processingUserGesture())
        removeBehaviorsRestrictionsAfterFirstUserGesture();

    if (document().settings().needsSiteSpecificQuirks() && m_dispatchingCanPlayEvent && !m_loadInitiatedByUserGesture) {
        // It should be impossible to be processing the canplay event while handling a user gesture
        // since it is dispatched asynchronously.
        ASSERT(!ScriptController::processingUserGesture());
        String host = document().baseURL().host().toString();
        if (host.endsWith(".npr.org", false) || equalLettersIgnoringASCIICase(host, "npr.org"))
            return;
    }

    playInternal();
}

void HTMLMediaElement::playInternal()
{
    gMediaLog("HTMLMediaElement(%p)::playInternal\n", this);

    if (!document().hasBrowsingContext()) {
    	gMediaLog("  returning because there is no browsing context");
        return;
    }

    // 4.8.10.9. Playing the media resource
    if (!m_player || m_networkState == NETWORK_EMPTY)
    	scheduleDelayedAction(LoadMediaResource);

    if (endedPlayback())
        seekInternal(MediaTime::zeroTime());

    if (m_mediaController)
        m_mediaController->bringElementUpToSpeed(this);

    if (m_paused) {
        m_paused = false;
        invalidateCachedTime();
        scheduleEvent(eventNames().playEvent);

        if (m_readyState <= HAVE_CURRENT_DATA)
            scheduleEvent(eventNames().waitingEvent);
        else if (m_readyState >= HAVE_FUTURE_DATA)
            scheduleEvent(eventNames().playingEvent);
    }
    m_autoplaying = false;

    updatePlayState();
    updateMediaController();
}

void HTMLMediaElement::pause()
{
    gMediaLog("HTMLMediaElement(%p)::pause()\n", this);

    if (userGestureRequiredForRateChange() && !ScriptController::processingUserGesture())
        return;

    pauseInternal();
}

void HTMLMediaElement::pauseInternal()
{
    gMediaLog("HTMLMediaElement(%p)::pauseInternal\n", this);

    if (!document().hasBrowsingContext()) {
    	gMediaLog("  returning because there is no browsing context");
        return;
    }

    // 4.8.10.9. Playing the media resource
    if (!m_player || m_networkState == NETWORK_EMPTY)
    	scheduleDelayedAction(LoadMediaResource);

    m_autoplaying = false;

    if (!m_paused) {
        m_paused = true;
        scheduleTimeupdateEvent(false);
        scheduleEvent(eventNames().pauseEvent);
#if 0
        m_promiseTaskQueue.enqueueTask([this]() {
            rejectPendingPlayPromises(DOMError::create("AbortError", "The operation was aborted."));
        });
#endif
    }

    updatePlayState();
}

#if ENABLE(MEDIA_SOURCE)
void HTMLMediaElement::detachMediaSource()
{
    if (!m_mediaSource)
        return;

    gMediaLog("HTMLMediaElement(%p)::detachMediaSource\n", this);

    m_mediaSource->detachFromElement(*this);
    m_mediaSource = nullptr;
}
#endif

#if ENABLE(LEGACY_ENCRYPTED_MEDIA)

HTMLMediaElement::PendingKeyRequest::PendingKeyRequest(const String& keySystem, Uint8Array* initData)
: keySystem(keySystem)
, initData(initData)
{
}

HTMLMediaElement::PendingKeyRequest::~PendingKeyRequest()
{
}

void HTMLMediaElement::generateKeyRequest(const String& keySystem, PassRefPtr<Uint8Array> initData, ExceptionCode& ec)
{
    gMediaLog("HTMLMediaElement(%p)::generateKeyRequest %s, mediaSource %p\n", this, keySystem.latin1().data(), m_mediaSource.get());

    if (keySystem.isEmpty()) {
        ec = SYNTAX_ERR;
        return;
    }

    if(!m_mediaSource || m_pendingKeyRequests.size() > 0) {
        gMediaLog("HTMLMediaElement(%p)::generateKeyRequest %s, no media source, queue requests.\n", this, keySystem.latin1().data());
    	m_pendingKeyRequests.append(PendingKeyRequest(keySystem, initData.get()));

    	if(m_mediaSource && !m_keyRequestTimer.isActive())
    		m_keyRequestTimer.startOneShot(0);

    	return;
    }

    if (!m_player) {
        gMediaLog("HTMLMediaElement(%p)::generateKeyRequest %s, no media player\n", this, keySystem.latin1().data());
        ec = INVALID_STATE_ERR;
        return;
    }

    const unsigned char* initDataPointer = 0;
    unsigned initDataLength = 0;
    if (initData) {
        initDataPointer = initData->data();
        initDataLength = initData->length();
    }

    MediaPlayer::MediaKeyException result = m_player->generateKeyRequest(keySystem, initDataPointer, initDataLength);
    ec = exceptionCodeForMediaKeyException(result);
}

void HTMLMediaElement::keyRequestTimerFired()
{
    while (!m_pendingKeyRequests.isEmpty()) {
        PendingKeyRequest request = m_pendingKeyRequests.takeFirst();

        gMediaLog("HTMLMediaElement(%p)::keyRequestTimerFired %s\n", this, request.keySystem.latin1().data());

        ExceptionCode ec;

        if (m_player) {
			const unsigned char* initDataPointer = 0;
			unsigned initDataLength = 0;
			if (request.initData) {
				initDataPointer = request.initData->data();
				initDataLength = request.initData->length();
			}

			MediaPlayer::MediaKeyException result = m_player->generateKeyRequest(request.keySystem, initDataPointer, initDataLength);
			ec = exceptionCodeForMediaKeyException(result);
        }
        else
            ec = INVALID_STATE_ERR;

        if(ec) {
            gMediaLog("HTMLMediaElement(%p)::keyRequestTimerFired %s ExceptionCode %i\n", this, request.keySystem.latin1().data(), ec);
        }
    }
}

void HTMLMediaElement::addKey(const String& keySystem, PassRefPtr<Uint8Array> key, PassRefPtr<Uint8Array> initData, const String& sessionId, ExceptionCode& ec)
{
    gMediaLog("HTMLMediaElement(%p)::addKey %s\n", this, keySystem.latin1().data());

    if (keySystem.isEmpty()) {
        ec = SYNTAX_ERR;
        return;
    }

    if (!key) {
        ec = SYNTAX_ERR;
        return;
    }

    if (!key->length()) {
        ec = TYPE_MISMATCH_ERR;
        return;
    }

    if (!m_player) {
        ec = INVALID_STATE_ERR;
        return;
    }

    const unsigned char* initDataPointer = 0;
    unsigned initDataLength = 0;
    if (initData) {
        initDataPointer = initData->data();
        initDataLength = initData->length();
    }

    MediaPlayer::MediaKeyException result = m_player->addKey(keySystem, key->data(), key->length(), initDataPointer, initDataLength, sessionId);
    ec = exceptionCodeForMediaKeyException(result);
}

void HTMLMediaElement::cancelKeyRequest(const String& keySystem, const String& sessionId, ExceptionCode& ec)
{
    gMediaLog("HTMLMediaElement(%p)::cancelKeyRequest %s\n", this, keySystem.latin1().data());

    if (keySystem.isEmpty()) {
        ec = SYNTAX_ERR;
        return;
    }

    if (!m_player) {
        ec = INVALID_STATE_ERR;
        return;
    }

    MediaPlayer::MediaKeyException result = m_player->cancelKeyRequest(keySystem, sessionId);
    ec = exceptionCodeForMediaKeyException(result);
}

#endif

bool HTMLMediaElement::loop() const
{
    return hasAttributeWithoutSynchronization(loopAttr);
}

void HTMLMediaElement::setLoop(bool b)
{
    gMediaLog("HTMLMediaElement(%p)::setLoop(%s)\n", this, boolString(b));
    setBooleanAttribute(loopAttr, b);
#if PLATFORM(MAC)
    updateDisableSleep();
#endif
}

bool HTMLMediaElement::controls() const
{
    Frame* frame = document().frame();

    // always show controls when scripting is disabled
    if (frame && !frame->script()->canExecuteScripts(NotAboutToExecuteScript))
        return true;

    // always show controls for video when fullscreen playback is required.
    if (isVideo() && document().page() && document().page()->chrome()->requiresFullscreenForVideoPlayback())
        return true;

    // Always show controls when in full screen mode.
    if (isFullscreen())
        return true;

    return hasAttributeWithoutSynchronization(controlsAttr);
}

void HTMLMediaElement::setControls(bool b)
{
    gMediaLog("HTMLMediaElement(%p)::setControls(%s)\n", this, boolString(b));
    setBooleanAttribute(controlsAttr, b);
}

double HTMLMediaElement::volume() const
{
    return m_volume;
}

void HTMLMediaElement::setVolume(double vol, ExceptionCode& ec)
{
    gMediaLog("HTMLMediaElement(%p)::setVolume(%f)\n", this, vol);

    if (vol < 0.0f || vol > 1.0f) {
        ec = INDEX_SIZE_ERR;
        return;
    }
    
    if (m_volume != vol) {
        m_volume = vol;
        updateVolume();
        scheduleEvent(eventNames().volumechangeEvent);
    }
}

bool HTMLMediaElement::muted() const
{
    return m_muted;
}

void HTMLMediaElement::setMuted(bool muted)
{
    gMediaLog("HTMLMediaElement(%p)::setMuted(%s)\n", this, boolString(muted));

    if (m_muted != muted) {
        m_muted = muted;
        // Avoid recursion when the player reports volume changes.
        if (!processingMediaPlayerCallback()) {
            if (m_player) {
                m_player->setMuted(m_muted);
                if (hasMediaControls())
                    mediaControls()->changedMute();
            }
        }
        scheduleEvent(eventNames().volumechangeEvent);
    }
}

void HTMLMediaElement::togglePlayState()
{
    gMediaLog("HTMLMediaElement(%p)::togglePlayState - canPlay() is %s\n", this, boolString(canPlay()));

    // We can safely call the internal play/pause methods, which don't check restrictions, because
    // this method is only called from the built-in media controller
    if (canPlay()) {
        updatePlaybackRate();
        playInternal();
    } else 
        pauseInternal();
}

void HTMLMediaElement::beginScrubbing()
{
    gMediaLog("HTMLMediaElement(%p)::beginScrubbing - paused() is %s\n", this, boolString(paused()));

    if (!paused()) {
        if (ended()) {
            // Because a media element stays in non-paused state when it reaches end, playback resumes 
            // when the slider is dragged from the end to another position unless we pause first. Do 
            // a "hard pause" so an event is generated, since we want to stay paused after scrubbing finishes.
            pause();
        } else {
            // Not at the end but we still want to pause playback so the media engine doesn't try to
            // continue playing during scrubbing. Pause without generating an event as we will 
            // unpause after scrubbing finishes.
            setPausedInternal(true);
        }
    }
}

void HTMLMediaElement::endScrubbing()
{
    gMediaLog("HTMLMediaElement(%p)::endScrubbing - m_pausedInternal is %s\n", this, boolString(m_pausedInternal));

    if (m_pausedInternal)
        setPausedInternal(false);
}

// The spec says to fire periodic timeupdate events (those sent while playing) every
// "15 to 250ms"
static const double maxTimeupdateEventFrequency = 0.2;
static const double minTimeupdateEventFrequency = 0.10;

void HTMLMediaElement::startPlaybackProgressTimer()
{
    if (m_playbackProgressTimer.isActive())
        return;

    m_previousProgressTime = monotonicallyIncreasingTime();
    m_playbackProgressTimer.startRepeating(maxTimeupdateEventFrequency);
}

void HTMLMediaElement::playbackProgressTimerFired()
{
    ASSERT(m_player);

    if (m_fragmentEndTime.isValid() && currentMediaTime() >= m_fragmentEndTime && effectivePlaybackRate() > 0) {
        m_fragmentEndTime = MediaTime::invalidTime();
        if (!m_mediaController && !m_paused) {
            // changes paused to true and fires a simple event named pause at the media element.
            pauseInternal();
        }
    }
    
    scheduleTimeupdateEvent(true);

    if (!effectivePlaybackRate())
        return;

    if (!m_paused && hasMediaControls())
        mediaControls()->playbackProgressed();
    
#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        updateActiveTextTrackCues(currentTime());
#endif
}

void HTMLMediaElement::scheduleTimeupdateEvent(bool periodicEvent)
{
    // Some media engines make multiple "time changed" callbacks at the same time, but we only want one
    // event at a given time so filter here
    MediaTime movieTime = currentMediaTime();

    if (periodicEvent || (movieTime != m_lastTimeUpdateEventMovieTime)){
        scheduleEvent(eventNames().timeupdateEvent);
        m_lastTimeUpdateEventMovieTime = movieTime;
    }
}

bool HTMLMediaElement::canPlay() const
{
    return paused() || ended() || m_readyState < HAVE_METADATA;
}

double HTMLMediaElement::percentLoaded() const
{
    if (!m_player)
        return 0;
    MediaTime duration = m_player->duration();

    if (!duration || duration.isPositiveInfinite() || duration.isNegativeInfinite())
        return 0;

    MediaTime buffered = MediaTime::zeroTime();
    bool ignored;
    OwnPtr<PlatformTimeRanges> timeRanges = m_player->buffered();
    for (unsigned i = 0; i < timeRanges->length(); ++i) {
        ExceptionCode ignoredException;
        MediaTime start = timeRanges->start(i, ignored);
        MediaTime end = timeRanges->end(i, ignored);
        buffered += end - start;
    }
    return buffered.toDouble() / duration.toDouble();
}

#if ENABLE(VIDEO_TRACK)

void HTMLMediaElement::mediaPlayerDidAddAudioTrack(PassRefPtr<AudioTrackPrivate> prpTrack)
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    addAudioTrack(AudioTrack::create(this, prpTrack));
}

void HTMLMediaElement::mediaPlayerDidAddAudioTrack(PassRefPtr<AudioTrack> track)
{
	addAudioTrack(track);
}

void HTMLMediaElement::mediaPlayerDidAddTextTrack(PassRefPtr<InbandTextTrackPrivate> prpTrack)
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;
    
    // 4.8.10.12.2 Sourcing in-band text tracks
    // 1. Associate the relevant data with a new text track and its corresponding new TextTrack object.
    RefPtr<InbandTextTrack> textTrack = InbandTextTrack::create(ActiveDOMObject::scriptExecutionContext(), this, prpTrack);
    
    // 2. Set the new text track's kind, label, and language based on the semantics of the relevant data,
    // as defined by the relevant specification. If there is no label in that data, then the label must
    // be set to the empty string.
    // 3. Associate the text track list of cues with the rules for updating the text track rendering appropriate
    // for the format in question.
    // 4. If the new text track's kind is metadata, then set the text track in-band metadata track dispatch type
    // as follows, based on the type of the media resource:
    // 5. Populate the new text track's list of cues with the cues parsed so far, folllowing the guidelines for exposing
    // cues, and begin updating it dynamically as necessary.
    //   - Thess are all done by the media engine.
    
    // 6. Set the new text track's readiness state to loaded.
    textTrack->setReadinessState(TextTrack::Loaded);
    
    // 7. Set the new text track's mode to the mode consistent with the user's preferences and the requirements of
    // the relevant specification for the data.
    //  - This will happen in configureTextTracks()
    scheduleDelayedAction(LoadTextTrackResource);
    
    // 8. Add the new text track to the media element's list of text tracks.
    // 9. Fire an event with the name addtrack, that does not bubble and is not cancelable, and that uses the TrackEvent
    // interface, with the track attribute initialized to the text track's TextTrack object, at the media element's
    // textTracks attribute's TextTrackList object.
    textTracks()->append(textTrack.release());
}

void HTMLMediaElement::mediaPlayerDidAddVideoTrack(PassRefPtr<VideoTrackPrivate> prpTrack)
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    addVideoTrack(VideoTrack::create(this, prpTrack));
}

void HTMLMediaElement::mediaPlayerDidRemoveAudioTrack(PassRefPtr<AudioTrackPrivate> prpTrack)
{
    prpTrack->willBeRemoved();
}

void HTMLMediaElement::mediaPlayerDidRemoveAllAudioTracks()
{
	if(!m_audioTracks)
		return;

	while(m_audioTracks->length() > 0)
		m_audioTracks->remove(m_audioTracks->item(0));
}

void HTMLMediaElement::mediaPlayerDidRemoveTextTrack(PassRefPtr<InbandTextTrackPrivate> prpTrack)
{
    prpTrack->willBeRemoved();
}

void HTMLMediaElement::mediaPlayerDidRemoveVideoTrack(PassRefPtr<VideoTrackPrivate> prpTrack)
{
    prpTrack->willBeRemoved();
}

void HTMLMediaElement::addAudioTrack(PassRefPtr<AudioTrack> track)
{
    gMediaLog("HTMLMediaElement(%p)::addAudioTrack\n", this);

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    audioTracks()->append(track);
}

void HTMLMediaElement::addTextTrack(PassRefPtr<TextTrack> track)
{
    gMediaLog("HTMLMediaElement(%p)::addTextTrack\n", this);

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    textTracks()->append(track);
}

void HTMLMediaElement::addVideoTrack(PassRefPtr<VideoTrack> track)
{
    gMediaLog("HTMLMediaElement(%p)::addVideoTrack\n", this);

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    videoTracks()->append(track);
}

void HTMLMediaElement::removeAudioTrack(AudioTrack* track)
{
    gMediaLog("HTMLMediaElement(%p)::removeAudioTrack\n", this);

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    m_audioTracks->remove(track);
}

void HTMLMediaElement::removeTextTrack(TextTrack* track)
{
    gMediaLog("HTMLMediaElement(%p)::removeTextTrack\n", this);

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    TextTrackCueList* cues = track->cues();
    if (cues)
        textTrackRemoveCues(track, cues);
    track->clearClient();
    m_textTracks->remove(track);
}

void HTMLMediaElement::removeVideoTrack(VideoTrack* track)
{
    gMediaLog("HTMLMediaElement(%p)::removeVideoTrack\n", this);

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    m_videoTracks->remove(track);
}

void HTMLMediaElement::removeAllInbandTracks()
{
    gMediaLog("HTMLMediaElement(%p)::removeAllInbandTracks\n", this);

    while (m_audioTracks && m_audioTracks->length())
        removeAudioTrack(m_audioTracks->lastItem());

    if (m_textTracks) {
        for (int i = m_textTracks->length() - 1; i >= 0; --i) {
            TextTrack* track = m_textTracks->item(i);

            if (track->trackType() == TextTrack::InBand)
                removeTextTrack(track);
        }
    }

    while (m_videoTracks &&  m_videoTracks->length())
        removeVideoTrack(m_videoTracks->lastItem());
}

PassRefPtr<TextTrack> HTMLMediaElement::addTextTrack(const String& kind, const String& label, const String& language, ExceptionCode& ec)
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return nullptr;

    // 4.8.10.12.4 Text track API
    // The addTextTrack(kind, label, language) method of media elements, when invoked, must run the following steps:

    // 1. If kind is not one of the following strings, then throw a SyntaxError exception and abort these steps
    if (!TextTrack::isValidKindKeyword(kind)) {
        ec = TypeError;
        return nullptr;
    }

    // 2. If the label argument was omitted, let label be the empty string.
    // 3. If the language argument was omitted, let language be the empty string.
    // 4. Create a new TextTrack object.

    // 5. Create a new text track corresponding to the new object, and set its text track kind to kind, its text 
    // track label to label, its text track language to language...
    RefPtr<TextTrack> textTrack = TextTrack::create(ActiveDOMObject::scriptExecutionContext(), this, kind, emptyAtom, label, language);

    // Note, due to side effects when changing track parameters, we have to
    // first append the track to the text track list.

    // 6. Add the new text track to the media element's list of text tracks.
    textTracks()->append(textTrack);

    // ... its text track readiness state to the text track loaded state ...
    textTrack->setReadinessState(TextTrack::Loaded);

    // ... its text track mode to the text track hidden mode, and its text track list of cues to an empty list ...
    textTrack->setMode(TextTrack::hiddenKeyword());

    if (hasMediaControls())
        mediaControls()->closedCaptionTracksChanged();

    return textTrack.release();
}

AudioTrackList* HTMLMediaElement::audioTracks()
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return 0;

    if (!m_audioTracks)
        m_audioTracks = AudioTrackList::create(this, ActiveDOMObject::scriptExecutionContext());

    return m_audioTracks.get();
}

TextTrackList* HTMLMediaElement::textTracks() 
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return 0;

    if (!m_textTracks)
        m_textTracks = TextTrackList::create(this, ActiveDOMObject::scriptExecutionContext());

    return m_textTracks.get();
}

VideoTrackList* HTMLMediaElement::videoTracks()
{
    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return 0;

    if (!m_videoTracks)
        m_videoTracks = VideoTrackList::create(this, ActiveDOMObject::scriptExecutionContext());

    return m_videoTracks.get();
}

void HTMLMediaElement::didAddTextTrack(HTMLTrackElement* trackElement)
{
    ASSERT(trackElement->hasTagName(trackTag));

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;

    // 4.8.10.12.3 Sourcing out-of-band text tracks
    // When a track element's parent element changes and the new parent is a media element, 
    // then the user agent must add the track element's corresponding text track to the 
    // media element's list of text tracks ... [continues in TextTrackList::append]
    RefPtr<TextTrack> textTrack = trackElement->track();
    if (!textTrack)
        return;
    
    textTracks()->append(textTrack.release());
    
    // Do not schedule the track loading until parsing finishes so we don't start before all tracks
    // in the markup have been added.
    if (!m_parsingInProgress)
    	scheduleDelayedAction(LoadTextTrackResource);

    if (hasMediaControls())
        mediaControls()->closedCaptionTracksChanged();
}

void HTMLMediaElement::didRemoveTextTrack(HTMLTrackElement* trackElement)
{
    ASSERT(trackElement->hasTagName(trackTag));

    if (!RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        return;
#if !LOG_DISABLED
    if (trackElement->hasTagName(trackTag)) {
        KURL url = trackElement->getNonEmptyURLAttribute(srcAttr);
        gMediaLog("HTMLMediaElement(%p)::didRemoveTrack - 'src' is %s\n", this, urlForLogging(url).utf8().data());
    }
#endif

    RefPtr<TextTrack> textTrack = trackElement->track();
    if (!textTrack)
        return;
    
    textTrack->setHasBeenConfigured(false);

    if (!m_textTracks)
        return;
    
    // 4.8.10.12.3 Sourcing out-of-band text tracks
    // When a track element's parent element changes and the old parent was a media element, 
    // then the user agent must remove the track element's corresponding text track from the 
    // media element's list of text tracks.
    m_textTracks->remove(textTrack.get());
    if (textTrack->cues()) {
        TextTrackCueList* cues = textTrack->cues();
        beginIgnoringTrackDisplayUpdateRequests();
        for (size_t i = 0; i < cues->length(); ++i)
            textTrackRemoveCue(cues->item(i)->track(), cues->item(i));
        endIgnoringTrackDisplayUpdateRequests();
    }

    if (hasMediaControls())
        mediaControls()->closedCaptionTracksChanged();

    size_t index = m_textTracksWhenResourceSelectionBegan.find(textTrack.get());
    if (index != notFound)
        m_textTracksWhenResourceSelectionBegan.remove(index);
}

bool HTMLMediaElement::userPrefersCaptions() const
{
    Page* page = document().page();
    if (!page)
        return false;

    PageGroup& group = page->group();
    return group.userHasCaptionPreferences() && group.userPrefersCaptions();
}

bool HTMLMediaElement::userIsInterestedInThisTrackKind(String kind) const
{
	if (m_disableCaptions)
		return false;

    bool userPrefersCaptionsOrSubtitles = m_closedCaptionsVisible || userPrefersCaptions();

    if (kind == TextTrack::subtitlesKeyword())
        return (document().settings().shouldDisplaySubtitles()) || userPrefersCaptionsOrSubtitles;
    if (kind == TextTrack::captionsKeyword())
        return (document().settings().shouldDisplayCaptions()) || userPrefersCaptionsOrSubtitles;
    if (kind == TextTrack::descriptionsKeyword())
        return document().settings().shouldDisplayTextDescriptions();

    return false;
}

void HTMLMediaElement::configureTextTrackGroup(const TrackGroup& group)
{
    ASSERT(group.tracks.size());

    gMediaLog("HTMLMediaElement(%p)::configureTextTrackGroup\n", this);

    String bestMatchingLanguage;
    if (group.hasSrcLang) {
        Vector<String> languages;
        languages.reserveInitialCapacity(group.tracks.size());
        for (size_t i = 0; i < group.tracks.size(); ++i) {
            String srcLanguage = group.tracks[i]->language();
            if (srcLanguage.length())
                languages.append(srcLanguage);
        }
        bestMatchingLanguage = preferredLanguageFromList(languages);
    }

    // First, find the track in the group that should be enabled (if any).
    RefPtr<TextTrack> trackToEnable;
    RefPtr<TextTrack> defaultTrack;
    RefPtr<TextTrack> fallbackTrack;
    for (size_t i = 0; !trackToEnable && i < group.tracks.size(); ++i) {
        RefPtr<TextTrack> textTrack = group.tracks[i];

        if (userIsInterestedInThisTrackKind(textTrack->kind())) {
            // * If the text track kind is { [subtitles or captions] [descriptions] } and the user has indicated an interest in having a
            // track with this text track kind, text track language, and text track label enabled, and there is no
            // other text track in the media element's list of text tracks with a text track kind of either subtitles
            // or captions whose text track mode is showing
            // ...
            // * If the text track kind is chapters and the text track language is one that the user agent has reason
            // to believe is appropriate for the user, and there is no other text track in the media element's list of
            // text tracks with a text track kind of chapters whose text track mode is showing
            //    Let the text track mode be showing.
            if (bestMatchingLanguage.length()) {
                if (textTrack->language() == bestMatchingLanguage)
                    trackToEnable = textTrack;
            } else if (textTrack->isDefault()) {
                // The user is interested in this type of track, but their language preference doesn't match any track so we will
                // enable the 'default' track.
                defaultTrack = textTrack;
            }

            // Remember the first track that doesn't match language or have 'default' to potentially use as fallback.
            if (!fallbackTrack)
                fallbackTrack = textTrack;
        } else if (!group.visibleTrack && !defaultTrack && textTrack->isDefault()) {
            // * If the track element has a default attribute specified, and there is no other text track in the media
            // element's list of text tracks whose text track mode is showing or showing by default
            //    Let the text track mode be showing by default.
            defaultTrack = textTrack.get();
        }
    }

    if (!trackToEnable && defaultTrack)
        trackToEnable = defaultTrack;

    // If no track matches the user's preferred language and non was marked 'default', enable the first track
    // because the user has explicitly stated a preference for this kind of track.
    if (!trackToEnable && fallbackTrack)
        trackToEnable = fallbackTrack;

    for (size_t i = 0; i < group.tracks.size(); ++i) {
        RefPtr<TextTrack> textTrack = group.tracks[i];
        
        if (trackToEnable == textTrack) {
            textTrack->setMode(TextTrack::showingKeyword());
            if (defaultTrack == textTrack)
                textTrack->setShowingByDefault(true);
        } else {
            if (textTrack->showingByDefault()) {
                // If there is a text track in the media element's list of text tracks whose text track
                // mode is showing by default, the user agent must furthermore change that text track's
                // text track mode to hidden.
                textTrack->setShowingByDefault(false);
                textTrack->setMode(TextTrack::hiddenKeyword());
            } else
                textTrack->setMode(TextTrack::disabledKeyword());
        }
    }

    if (trackToEnable && group.defaultTrack && group.defaultTrack != trackToEnable) {
        if (group.defaultTrack && group.defaultTrack->showingByDefault()) {
            group.defaultTrack->setShowingByDefault(false);
            group.defaultTrack->setMode(TextTrack::hiddenKeyword());
        }
    }
}

void HTMLMediaElement::toggleTrackAtIndex(int index, bool exclusive)
{
    TextTrackList* trackList = textTracks();
    if (!trackList || !trackList->length())
        return;

    for (int i = 0, length = trackList->length(); i < length; ++i) {
        TextTrack* track = trackList->item(i);
        track->setShowingByDefault(false);
        if (i == index)
            track->setMode(TextTrack::showingKeyword());
        else if (exclusive || index == HTMLMediaElement::textTracksOffIndex())
            track->setMode(TextTrack::disabledKeyword());
    }
}

void HTMLMediaElement::configureTextTracks()
{
    TrackGroup captionAndSubtitleTracks(TrackGroup::CaptionsAndSubtitles);
    TrackGroup descriptionTracks(TrackGroup::Description);
    TrackGroup chapterTracks(TrackGroup::Chapter);
    TrackGroup metadataTracks(TrackGroup::Metadata);
    TrackGroup otherTracks(TrackGroup::Other);

    if (!m_textTracks)
        return;

    for (size_t i = 0; i < m_textTracks->length(); ++i) {
        RefPtr<TextTrack> textTrack = m_textTracks->item(i);
        if (!textTrack)
            continue;

        String kind = textTrack->kind();
        TrackGroup* currentGroup;
        if (kind == TextTrack::subtitlesKeyword() || kind == TextTrack::captionsKeyword())
            currentGroup = &captionAndSubtitleTracks;
        else if (kind == TextTrack::descriptionsKeyword())
            currentGroup = &descriptionTracks;
        else if (kind == TextTrack::chaptersKeyword())
            currentGroup = &chapterTracks;
        else if (kind == TextTrack::metadataKeyword())
            currentGroup = &metadataTracks;
        else
            currentGroup = &otherTracks;

        if (!currentGroup->visibleTrack && textTrack->mode() == TextTrack::showingKeyword())
            currentGroup->visibleTrack = textTrack;
        if (!currentGroup->defaultTrack && textTrack->isDefault())
            currentGroup->defaultTrack = textTrack;

        // Do not add this track to the group if it has already been automatically configured
        // as we only want to call configureTextTrack once per track so that adding another 
        // track after the initial configuration doesn't reconfigure every track - only those 
        // that should be changed by the new addition. For example all metadata tracks are 
        // disabled by default, and we don't want a track that has been enabled by script 
        // to be disabled automatically when a new metadata track is added later.
        if (textTrack->hasBeenConfigured())
            continue;
        
        if (textTrack->language().length())
            currentGroup->hasSrcLang = true;
        currentGroup->tracks.append(textTrack);
    }
    
    if (captionAndSubtitleTracks.tracks.size())
        configureTextTrackGroup(captionAndSubtitleTracks);
    if (descriptionTracks.tracks.size())
        configureTextTrackGroup(descriptionTracks);
    if (chapterTracks.tracks.size())
        configureTextTrackGroup(chapterTracks);
    if (metadataTracks.tracks.size())
        configureTextTrackGroup(metadataTracks);
    if (otherTracks.tracks.size())
        configureTextTrackGroup(otherTracks);

    if (hasMediaControls())
        mediaControls()->closedCaptionTracksChanged();
}
#endif

bool HTMLMediaElement::havePotentialSourceChild()
{
    // Stash the current <source> node and next nodes so we can restore them after checking
    // to see there is another potential.
    RefPtr<HTMLSourceElement> currentSourceNode = m_currentSourceNode;
    RefPtr<Node> nextNode = m_nextChildNodeToConsider;

    KURL nextURL = selectNextSourceChild(0, 0, DoNothing);

    m_currentSourceNode = currentSourceNode;
    m_nextChildNodeToConsider = nextNode;

    return nextURL.isValid();
}

KURL HTMLMediaElement::selectNextSourceChild(ContentType* contentType, String* keySystem, InvalidURLAction actionIfInvalid)
{
#if !LOG_DISABLED
    // Don't log if this was just called to find out if there are any valid <source> elements.
    bool shouldLog = actionIfInvalid != DoNothing;
    if (shouldLog)
        gMediaLog("HTMLMediaElement(%p)::selectNextSourceChild\n", this);
#endif

    if (!m_nextChildNodeToConsider) {
#if !LOG_DISABLED
        if (shouldLog)
            gMediaLog("HTMLMediaElement(%p)::selectNextSourceChild -> 0x0000, \"\"\n", this);
#endif
        return KURL();
    }

    KURL mediaURL;
    HTMLSourceElement* source = nullptr;
    String type;
    String system;
    bool lookingForStartNode = m_nextChildNodeToConsider.get();
    bool canUseSourceElement = false;

    NodeVector potentialSourceNodes;
    collectChildNodes(*this, potentialSourceNodes);
    for (unsigned i = 0; !canUseSourceElement && i < potentialSourceNodes.size(); ++i) {
        Node& node = potentialSourceNodes[i].get();
        if (lookingForStartNode && m_nextChildNodeToConsider != &node)
            continue;
        lookingForStartNode = false;

        if (!node.hasTagName(sourceTag))
            continue;
        if (node.parentNode() != this)
            continue;

        source = &static_cast<HTMLSourceElement&>(node);

        // If candidate does not have a src attribute, or if its src attribute's value is the empty string ... jump down to the failed step below
        mediaURL = source->getNonEmptyURLAttribute(srcAttr);
#if !LOG_DISABLED
        if (shouldLog)
            gMediaLog("HTMLMediaElement(%p)::selectNextSourceChild - 'src' is %s\n", this, urlForLogging(mediaURL).utf8().data());
#endif
        if (mediaURL.isEmpty())
            goto CheckAgain;
        
        if (source->hasAttributeWithoutSynchronization(mediaAttr)) {
            MediaQueryEvaluator screenEval("screen", document(), renderer() ? renderer()->style() : 0);
            RefPtr<MediaQuerySet> media = MediaQuerySet::create(source->getAttribute(mediaAttr));
#if !LOG_DISABLED
            if (shouldLog)
                gMediaLog("HTMLMediaElement(%p)::selectNextSourceChild - 'media' is %s\n", this, source->media().utf8().data());
#endif
            if (!screenEval.evaluate(*media))
                goto CheckAgain;
        }

        type = source->getAttribute(typeAttr);
        // FIXME(82965): Add support for keySystem in <source> and set system from source.
        if (type.isEmpty() && mediaURL.protocolIsData())
            type = mimeTypeFromDataURL(mediaURL);
        if (!type.isEmpty() || !system.isEmpty()) {
#if !LOG_DISABLED
            if (shouldLog)
                gMediaLog("HTMLMediaElement(%p)::selectNextSourceChild - 'type' is '%s' - key system is '%s'\n", this, type.utf8().data(), system.utf8().data());
#endif
            MediaEngineSupportParameters parameters;
            ContentType contentType(type);
            parameters.type = contentType.type().lower();
            parameters.codecs = contentType.parameter(ASCIILiteral("codecs"));
            parameters.url = mediaURL;
#if ENABLE(ENCRYPTED_MEDIA)
            parameters.keySystem = system;
#endif
#if ENABLE(MEDIA_SOURCE)
            parameters.isMediaSource = mediaURL.protocolIs(mediaSourceBlobProtocol);
#endif
#if ENABLE(MEDIA_STREAM)
            parameters.isMediaStream = mediaURL.protocolIs(mediaStreamBlobProtocol);
#endif
            if (!MediaPlayer::supportsType(parameters, this))
                goto CheckAgain;
        }

        // Is it safe to load this url?
        if (!isSafeToLoadURL(mediaURL, actionIfInvalid))
            goto CheckAgain;

        // A 'beforeload' event handler can mutate the DOM, so check to see if the source element is still a child node.
        if (node.parentNode() != this) {
            gMediaLog("HTMLMediaElement(%p)::selectNextSourceChild : 'beforeload' removed current element\n", this);
            source = nullptr;
            goto CheckAgain;
        }

        // Making it this far means the <source> looks reasonable.
        canUseSourceElement = true;

CheckAgain:
        if (!canUseSourceElement && actionIfInvalid == Complain && source)
            source->scheduleErrorEvent();
    }

    if (canUseSourceElement) {
        if (contentType)
            *contentType = ContentType(type);
        if (keySystem)
            *keySystem = system;
        m_currentSourceNode = source;
        m_nextChildNodeToConsider = source->nextSibling();
    } else {
        m_currentSourceNode = nullptr;
        m_nextChildNodeToConsider = nullptr;
    }

#if !LOG_DISABLED
    if (shouldLog)
        gMediaLog("HTMLMediaElement(%p)::selectNextSourceChild -> %p, %s\n", this, m_currentSourceNode.get(), canUseSourceElement ? urlForLogging(mediaURL).utf8().data() : "");
#endif
    return canUseSourceElement ? mediaURL : KURL();
}

void HTMLMediaElement::sourceWasAdded(HTMLSourceElement* source)
{
    gMediaLog("HTMLMediaElement(%p)::sourceWasAdded(%p)\n", this, source);

#if !LOG_DISABLED
    if (source->hasTagName(sourceTag)) {
        KURL url = source->getNonEmptyURLAttribute(srcAttr);
        gMediaLog("HTMLMediaElement(%p)::sourceWasAdded - 'src' is %s\n", this, urlForLogging(url).utf8().data());
    }
#endif

    if (!document().hasBrowsingContext()) {
    	gMediaLog("<source> inserted inside a document without a browsing context is not loaded");
        return;
    }

    // We should only consider a <source> element when there is not src attribute at all.
    if (hasAttributeWithoutSynchronization(srcAttr))
        return;

    // 4.8.8 - If a source element is inserted as a child of a media element that has no src 
    // attribute and whose networkState has the value NETWORK_EMPTY, the user agent must invoke 
    // the media element's resource selection algorithm.
    if (networkState() == HTMLMediaElement::NETWORK_EMPTY) {
    	scheduleDelayedAction(LoadMediaResource);
        m_nextChildNodeToConsider = source;
        return;
    }

    if (m_currentSourceNode && source == m_currentSourceNode->nextSibling()) {
        gMediaLog("HTMLMediaElement(%p)::sourceWasAdded - <source> inserted immediately after current source\n", this);
        m_nextChildNodeToConsider = source;
        return;
    }

    if (m_nextChildNodeToConsider)
        return;
    
    // 4.8.9.5, resource selection algorithm, source elements section:
    // 21. Wait until the node after pointer is a node other than the end of the list. (This step might wait forever.)
    // 22. Asynchronously await a stable state...
    // 23. Set the element's delaying-the-load-event flag back to true (this delays the load event again, in case 
    // it hasn't been fired yet).
    setShouldDelayLoadEvent(true);

    // 24. Set the networkState back to NETWORK_LOADING.
    m_networkState = NETWORK_LOADING;
    
    // 25. Jump back to the find next candidate step above.
    m_nextChildNodeToConsider = source;
    scheduleNextSourceChild();
}

void HTMLMediaElement::sourceWasRemoved(HTMLSourceElement* source)
{
    gMediaLog("HTMLMediaElement(%p)::sourceWasRemoved(%p)\n", this, source);

#if !LOG_DISABLED
    if (source->hasTagName(sourceTag)) {
        KURL url = source->getNonEmptyURLAttribute(srcAttr);
        gMediaLog("HTMLMediaElement(%p)::sourceWasRemoved - 'src' is %s\n", this, urlForLogging(url).utf8().data());
    }
#endif

    if (source != m_currentSourceNode && source != m_nextChildNodeToConsider)
        return;

    if (source == m_nextChildNodeToConsider) {
        if (m_currentSourceNode)
            m_nextChildNodeToConsider = m_currentSourceNode->nextSibling();
        gMediaLog("HTMLMediaElement(%p)::sourceRemoved - m_nextChildNodeToConsider set to %p\n", this, m_nextChildNodeToConsider.get());
    } else if (source == m_currentSourceNode) {
        // Clear the current source node pointer, but don't change the movie as the spec says:
        // 4.8.8 - Dynamically modifying a source element and its attribute when the element is already 
        // inserted in a video or audio element will have no effect.
        m_currentSourceNode = 0;
        gMediaLog("HTMLMediaElement(%p)::sourceRemoved - m_currentSourceNode set to 0\n", this);
    }
}

void HTMLMediaElement::mediaPlayerTimeChanged(MediaPlayer*, bool playEnded)
{
    //gMediaLog("HTMLMediaElement(%p)::mediaPlayerTimeChanged (m_seeking %i, m_readyState %i, m_player->seeking() %i)\n", this, m_seeking, m_readyState, m_player->seeking());

#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        updateActiveTextTrackCues(currentTime());
#endif

    beginProcessingMediaPlayerCallback();

    invalidateCachedTime();

    // 4.8.10.9 step 14 & 15.  Needed if no ReadyState change is associated with the seek.
    if (m_seeking && m_readyState >= HAVE_CURRENT_DATA && !m_player->seeking())
        finishSeek();
    
    // Always call scheduleTimeupdateEvent when the media engine reports a time discontinuity, 
    // it will only queue a 'timeupdate' event if we haven't already posted one at the current
    // movie time.
    scheduleTimeupdateEvent(false);

    MediaTime now = currentMediaTime();
    MediaTime dur = durationMediaTime();
    double playbackRate = effectivePlaybackRate();

    // When the current playback position reaches the end of the media resource then the user agent must follow these steps:
    if (dur && dur.isValid() && !dur.isPositiveInfinite() && !dur.isNegativeInfinite()) {
        // If the media element has a loop attribute specified and does not have a current media controller,
        if (loop() && !m_mediaController && playbackRate > 0) {
            m_sentEndEvent = false;

            // then seek to the earliest possible position of the media resource and abort these steps when the direction of
            // playback is forwards,
            if (playEnded || now >= dur) {
                gMediaLog("HTMLMediaElement(%p)::mediaPlayerTimeChanged(playEnded) playbackRate %f loop %i\n", this, playbackRate, loop());

				if(!seekInternal(MediaTime::zeroTime())) { // seek failed, re-play the media
					double playbackRate = m_playbackRate;

					// reset
					m_networkState = NETWORK_EMPTY;
					m_readyState = HAVE_NOTHING;
					m_readyStateMaximum = HAVE_NOTHING;
					m_paused = true;
					m_seeking = false;

					play();

					// restore play back rate when it is changed back to default play back rate in prepareForLoad
					if (playbackRate != m_playbackRate)
						setPlaybackRate(playbackRate);
				}
			}
        } else if (playEnded || (now <= MediaTime::zeroTime() && playbackRate < 0) || (now >= dur && playbackRate > 0)) {
            gMediaLog("HTMLMediaElement(%p)::mediaPlayerTimeChanged(playEnded) playbackRate %f loop %i\n", this, playbackRate, loop());

            // If the media element does not have a current media controller, and the media element
            // has still ended playback and paused is false,
            if (!m_mediaController && !m_paused) {
                // changes paused to true and fires a simple event named pause at the media element.
                m_paused = true;
                scheduleEvent(eventNames().pauseEvent);
            }
            // Queue a task to fire a simple event named ended at the media element.
            if (!m_sentEndEvent) {
                m_sentEndEvent = true;
                scheduleEvent(eventNames().endedEvent);
            }
            else
                gMediaLog("HTMLMediaElement(%p)::mediaPlayerTimeChanged(playEnded) already sent ended event\n", this);

            // If the media element has a current media controller, then report the controller state
            // for the media element's current media controller.
            updateMediaController();
        } else
            m_sentEndEvent = false;
    }
    else {
#if ENABLE(MEDIA_STREAM)
        if (m_mediaStreamSrcObject) {
            // http://w3c.github.io/mediacapture-main/#event-mediastream-inactive
            // 6. MediaStreams in Media Elements
            // When the MediaStream state moves from the active to the inactive state, the User Agent
            // must raise an ended event on the HTMLMediaElement and set its ended attribute to true.
            // Note that once ended equals true the HTMLMediaElement will not play media even if new
            // MediaStreamTrack's are added to the MediaStream (causing it to return to the active
            // state) unless autoplay is true or the web application restarts the element, e.g.,
            // by calling play()
            if (!m_sentEndEvent && m_player && m_player->ended()) {
                m_sentEndEvent = true;
                scheduleEvent(eventNames().endedEvent);
                m_paused = true;
                setPlaying(false);
            }
        } else
#endif
        m_sentEndEvent = false;
    }

    updatePlayState(false);
    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerScheduleEvent(MediaPlayer*, const String& eventName)
{
    scheduleEvent(eventName);
}

void HTMLMediaElement::mediaPlayerVolumeChanged(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerVolumeChanged\n", this);

    beginProcessingMediaPlayerCallback();
    if (m_player) {
        double vol = m_player->volume();
        if (vol != m_volume) {
            m_volume = vol;
            updateVolume();
            scheduleEvent(eventNames().volumechangeEvent);
        }
    }
    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerMuteChanged(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerMuteChanged\n", this);

    beginProcessingMediaPlayerCallback();
    if (m_player)
        setMuted(m_player->muted());
    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerDurationChanged(MediaPlayer* player)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerDurationChanged\n", this);

    beginProcessingMediaPlayerCallback();

    scheduleEvent(eventNames().durationchangeEvent);
    mediaPlayerCharacteristicChanged(player);

    MediaTime now = currentMediaTime();
    MediaTime dur = durationMediaTime();
    if (now > dur)
    	seekInternal(dur);

    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerRateChanged(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerRateChanged\n", this);

    beginProcessingMediaPlayerCallback();

    // Stash the rate in case the one we tried to set isn't what the engine is
    // using (eg. it can't handle the rate we set)
    m_playbackRate = m_player->rate();
    if (m_playing)
        invalidateCachedTime();

#if PLATFORM(MAC)
    updateDisableSleep();
#endif

    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerPlaybackStateChanged(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerPlaybackStateChanged\n", this);

    if (!m_player || m_pausedInternal)
        return;

    beginProcessingMediaPlayerCallback();
    if (m_player->paused())
        pauseInternal();
    else
        playInternal();
    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerSawUnsupportedTracks(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerSawUnsupportedTracks\n", this);

    // The MediaPlayer came across content it cannot completely handle.
    // This is normally acceptable except when we are in a standalone
    // MediaDocument. If so, tell the document what has happened.
    if (document().isMediaDocument()) {
        MediaDocument& mediaDocument = static_cast<MediaDocument&>(document());
        mediaDocument.mediaElementSawUnsupportedTracks();
    }
}

void HTMLMediaElement::mediaPlayerResourceNotSupported(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerResourceNotSupported\n", this);

    // The MediaPlayer came across content which no installed engine supports.
    mediaLoadingFailed(MediaPlayer::FormatError);
}

// MediaPlayerPresentation methods
void HTMLMediaElement::mediaPlayerRepaint(MediaPlayer*)
{
    beginProcessingMediaPlayerCallback();
    updateDisplayState();
    if (renderer())
        renderer()->repaint();
    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerSizeChanged(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerSizeChanged\n", this);

    beginProcessingMediaPlayerCallback();
    if (renderer())
        renderer()->updateFromElement();
    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerPlatformError(MediaPlayer*, unsigned short errorCode)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerError(code %i)\n", this, errorCode);

	m_error = MediaError::create(errorCode);
	scheduleEvent(eventNames().errorEvent);
}

#if USE(ACCELERATED_COMPOSITING)
bool HTMLMediaElement::mediaPlayerRenderingCanBeAccelerated(MediaPlayer*)
{
    if (renderer() && renderer()->isVideo())
        return renderer()->view().compositor().canAccelerateVideoRendering(*toRenderVideo(renderer()));
    return false;
}

void HTMLMediaElement::mediaPlayerRenderingModeChanged(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerRenderingModeChanged\n", this);

    // Kick off a fake recalcStyle that will update the compositing tree.
    invalidateStyleAndLayerComposition();
}
#endif

#if PLATFORM(WIN) && USE(AVFOUNDATION)
GraphicsDeviceAdapter* HTMLMediaElement::mediaPlayerGraphicsDeviceAdapter(const MediaPlayer*) const
{
    if (!document().page())
        return 0;

    return document().page()->chrome()->client()->graphicsDeviceAdapter();
}
#endif

void HTMLMediaElement::mediaPlayerEngineUpdated(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerEngineUpdated\n", this);
    beginProcessingMediaPlayerCallback();
    if (renderer())
        renderer()->updateFromElement();
    endProcessingMediaPlayerCallback();

#if ENABLE(MEDIA_SOURCE)
    m_droppedVideoFrames = 0;
#endif
}

void HTMLMediaElement::mediaPlayerFirstVideoFrameAvailable(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerFirstVideoFrameAvailable\n", this);
    beginProcessingMediaPlayerCallback();
    if (displayMode() == PosterWaitingForVideo) {
        setDisplayMode(Video);
#if USE(ACCELERATED_COMPOSITING)
        mediaPlayerRenderingModeChanged(m_player.get());
#endif
    }
    endProcessingMediaPlayerCallback();
}

void HTMLMediaElement::mediaPlayerCharacteristicChanged(MediaPlayer*)
{
    gMediaLog("HTMLMediaElement(%p)::mediaPlayerCharacteristicChanged\n", this);
    
    beginProcessingMediaPlayerCallback();
    if (hasMediaControls())
        mediaControls()->reset();
    if (renderer())
        renderer()->updateFromElement();
    endProcessingMediaPlayerCallback();
}

PassRefPtr<TimeRanges> HTMLMediaElement::buffered() const
{
    if (!m_player)
        return TimeRanges::create();

#if ENABLE(MEDIA_SOURCE)
    if (m_mediaSource)
        return TimeRanges::create(*m_mediaSource->buffered());
#endif

    return TimeRanges::create(*m_player->buffered());
}

PassRefPtr<TimeRanges> HTMLMediaElement::played()
{
    if (m_playing) {
        MediaTime time = currentMediaTime();
        if (time > m_lastSeekTime)
            addPlayedRange(m_lastSeekTime, time);
    }

    if (!m_playedTimeRanges)
        m_playedTimeRanges = TimeRanges::create();

    return m_playedTimeRanges->copy();
}

PassRefPtr<TimeRanges> HTMLMediaElement::seekable() const
{
#if ENABLE(MEDIA_SOURCE)
    if (m_mediaSource)
        return TimeRanges::create(*m_mediaSource->seekable());
#endif

    if (m_player)
        return TimeRanges::create(*m_player->seekable());

    return TimeRanges::create();
}

bool HTMLMediaElement::potentiallyPlaying() const
{
    // "pausedToBuffer" means the media engine's rate is 0, but only because it had to stop playing
    // when it ran out of buffered data. A movie is this state is "potentially playing", modulo the
    // checks in couldPlayIfEnoughData().
    bool pausedToBuffer = m_readyStateMaximum >= HAVE_FUTURE_DATA && m_readyState < HAVE_FUTURE_DATA;
    return (pausedToBuffer || m_readyState >= HAVE_FUTURE_DATA) && couldPlayIfEnoughData() && !isBlockedOnMediaController();
}

bool HTMLMediaElement::couldPlayIfEnoughData() const
{
    return !paused() && !endedPlayback() && !stoppedDueToErrors() && !pausedForUserInteraction();
}

bool HTMLMediaElement::endedPlayback() const
{
    MediaTime dur = durationMediaTime();
    if (!m_player || !dur.isValid())
        return false;

    // 4.8.10.8 Playing the media resource

    // A media element is said to have ended playback when the element's 
    // readyState attribute is HAVE_METADATA or greater, 
    if (m_readyState < HAVE_METADATA)
        return false;

    // and the current playback position is the end of the media resource and the direction
    // of playback is forwards, Either the media element does not have a loop attribute specified,
    // or the media element has a current media controller.
    MediaTime now = currentMediaTime();
    if (effectivePlaybackRate() > 0) {
        if(dur > MediaTime::zeroTime() && now >= dur && (!loop() || m_mediaController)) {
            gMediaLog("HTMLMediaElement(%p)::endedPlayback return true (now %s, duration %s)\n", this, toString(now).utf8().data(), toString(dur).utf8().data());
        	return true;
        }
    }
    // or the current playback position is the earliest possible position and the direction 
    // of playback is backwards
    else if (effectivePlaybackRate() < 0)
        return now <= MediaTime::zeroTime();

    return false;
}

bool HTMLMediaElement::stoppedDueToErrors() const
{
    if (m_readyState >= HAVE_METADATA && m_error) {
    	switch(m_error->code()) {
			case MediaError::MEDIA_ERR_RESOURCE_BUSY:
			case MediaError::MEDIA_ERR_NO_TUNER:
			case MediaError::MEDIA_ERR_NO_SIGNAL:
			case MediaError::MEDIA_ERR_NO_RIGHTS:
			case MediaError::MEDIA_ERR_CA_ERROR:
				return false;
			default:
				break;
    	}

        RefPtr<TimeRanges> seekableRanges = seekable();
        if (!seekableRanges->contain(currentTime())) {
            gMediaLog("HTMLMediaElement(%p)::stoppedDueToErrors return true\n", this);
            return true;
        }
    }
    
    return false;
}

bool HTMLMediaElement::pausedForUserInteraction() const
{
//    return !paused() && m_readyState >= HAVE_FUTURE_DATA && [UA requires a decitions from the user]
    return false;
}

MediaTime HTMLMediaElement::minTimeSeekable() const
{
    return m_player ? m_player->minTimeSeekable() : MediaTime::zeroTime();
}

MediaTime HTMLMediaElement::maxTimeSeekable() const
{
    return m_player ? m_player->maxTimeSeekable() : MediaTime::zeroTime();
}
    
void HTMLMediaElement::updateVolume()
{
    if (!m_player)
        return;

    // Avoid recursion when the player reports volume changes.
    if (!processingMediaPlayerCallback()) {
        Page* page = document().page();
        double volumeMultiplier = page ? page->mediaVolume() : 1;
        bool shouldMute = m_muted;

        if (m_mediaController) {
            volumeMultiplier *= m_mediaController->volume();
            shouldMute = m_mediaController->muted();
        }

        m_player->setMuted(shouldMute);
        m_player->setVolume(m_volume * volumeMultiplier);
    }

    if (hasMediaControls())
        mediaControls()->changedVolume();
}

void HTMLMediaElement::updatePlayState(bool shouldLog)
{
    if (!m_player)
        return;

    if (m_pausedInternal) {
        if (!m_player->paused())
            m_player->pause();
        refreshCachedTime();
        m_playbackProgressTimer.stop();
        if (hasMediaControls())
            mediaControls()->playbackStopped();
        return;
    }
    
    bool shouldBePlaying = potentiallyPlaying();
    bool playerPaused = m_player->paused();

    if(shouldLog)
    	gMediaLog("HTMLMediaElement(%p)::updatePlayState - shouldBePlaying = %s, playerPaused = %s\n", this, boolString(shouldBePlaying), boolString(playerPaused));

    if (shouldBePlaying) {
        setDisplayMode(Video);
        invalidateCachedTime();

        if (playerPaused) {
            if (!m_isFullscreen && isVideo() && document().page() && document().page()->chrome()->requiresFullscreenForVideoPlayback())
                enterFullscreen();

            // Set rate, muted before calling play in case they were set before the media engine was setup.
            // The media engine should just stash the rate and muted values since it isn't already playing.
            m_player->setRate(effectivePlaybackRate());
            m_player->setMuted(m_muted);

            m_player->play();
        }

        if (hasMediaControls())
            mediaControls()->playbackStarted();
        startPlaybackProgressTimer();
        m_playing = true;

    } else { // Should not be playing right now
        if (!playerPaused)
            m_player->pause();
        refreshCachedTime();

        m_playbackProgressTimer.stop();
        m_playing = false;
        MediaTime time = currentMediaTime();
        if (time > m_lastSeekTime)
            addPlayedRange(m_lastSeekTime, time);

        if (couldPlayIfEnoughData())
            prepareToPlay();

        if (hasMediaControls())
            mediaControls()->playbackStopped();
    }

    updateMediaController();

    if (renderer())
        renderer()->updateFromElement();
}

void HTMLMediaElement::setPlaying(bool playing)
{
    if (m_playing == playing)
        return;

    m_playing = playing;

#if 0
#if ENABLE(MEDIA_SESSION)
    document().updateIsPlayingMedia(m_elementID);
#else
    document().updateIsPlayingMedia();
#endif

#if ENABLE(WIRELESS_PLAYBACK_TARGET)
    updateMediaState(UpdateMediaState::Asynchronously);
#endif
#endif
}

void HTMLMediaElement::setPausedInternal(bool b)
{
    m_pausedInternal = b;
    updatePlayState();
}

void HTMLMediaElement::stopPeriodicTimers()
{
    m_progressEventTimer.stop();
    m_playbackProgressTimer.stop();
}

void HTMLMediaElement::userCancelledLoad()
{
    gMediaLog("HTMLMediaElement(%p)::userCancelledLoad\n", this);

    if (m_networkState == NETWORK_EMPTY || m_completelyLoaded)
        return;

    // If the media data fetching process is aborted by the user:

    // 1 - The user agent should cancel the fetching process.
    clearMediaPlayer(-1, false);

    // 2 - Set the error attribute to a new MediaError object whose code attribute is set to MEDIA_ERR_ABORTED.
    m_error = MediaError::create(MediaError::MEDIA_ERR_ABORTED);

    // 3 - Queue a task to fire a simple event named error at the media element.
    scheduleEvent(eventNames().abortEvent);

#if ENABLE(MEDIA_SOURCE)
    detachMediaSource();
#endif

    // 4 - If the media element's readyState attribute has a value equal to HAVE_NOTHING, set the 
    // element's networkState attribute to the NETWORK_EMPTY value and queue a task to fire a 
    // simple event named emptied at the element. Otherwise, set the element's networkState 
    // attribute to the NETWORK_IDLE value.
    if (m_readyState == HAVE_NOTHING) {
        m_networkState = NETWORK_EMPTY;
        scheduleEvent(eventNames().emptiedEvent);
    }
    else
        m_networkState = NETWORK_IDLE;

    // 5 - Set the element's delaying-the-load-event flag to false. This stops delaying the load event.
    setShouldDelayLoadEvent(false);

    // 6 - Abort the overall resource selection algorithm.
    m_currentSourceNode = 0;

    // Reset m_readyState since m_player is gone.
    m_readyState = HAVE_NOTHING;
    updateMediaController();
#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled())
        updateActiveTextTrackCues(0);
#endif
}

void HTMLMediaElement::clearMediaPlayer(int flags, bool willLoadNewURL)
{
#if ENABLE(MEDIA_SOURCE)
    detachMediaSource();
#endif

#if !ENABLE(PLUGIN_PROXY_FOR_VIDEO)

#if ENABLE(MEDIA_SOURCE)
	if(m_mediaSource){
	    if(m_player)
	    	m_player->clearMediaPlayerClient();
		m_player = nullptr;
	}
#endif

    if(m_player){
    	if(!willLoadNewURL || !m_player->supportsLoadingNewURL()){
    	   	m_player->clearMediaPlayerClient();
    		m_player.clear();
    	}
    	else
    		m_player->prepareForLoad();
    }
#endif

    stopPeriodicTimers();
    m_loadTimer.stop();

    m_pendingActionFlags &= ~flags;
    m_loadState = WaitingForSource;

#if ENABLE(VIDEO_TRACK)
    if (m_textTracks)
        configureTextTrackDisplay();
#endif
}

void HTMLMediaElement::documentWillBecomeInactive()
{
	clearMediaPlayer(-1, false);

#if ENABLE(MEDIA_SOURCE)
	detachMediaSource();
#endif

	userCancelledLoad();
}

bool HTMLMediaElement::canSuspendForDocumentSuspension() const
{
    return true; 
}

void HTMLMediaElement::stopWithoutDestroyingMediaPlayer()
{
    LOG(Media, "HTMLMediaElement::stopWithoutDestroyingMediaPlayer(%p)", this);

    if (m_isFullscreen)
		exitFullscreen();

	m_inActiveDocument = false;

	// Stop the playback without generating events
	m_playing = false;
	setPausedInternal(true);

	userCancelledLoad();

	if (renderer())
		renderer()->updateFromElement();

	stopPeriodicTimers();
}

void HTMLMediaElement::stop()
{
    gMediaLog("HTMLMediaElement(%p)::stop\n", this);

    stopWithoutDestroyingMediaPlayer();

    m_asyncEventQueue->close();

    // Once an active DOM object has been stopped it can not be restarted, so we can deallocate
    // the media player now. Note that userCancelledLoad will already have cleared the player
    // if the media was not fully loaded. This handles all other cases.
    if(m_player)
    	m_player->clearMediaPlayerClient();
    m_player.clear();
}

void HTMLMediaElement::suspend(ReasonForSuspension why)
{
    gMediaLog("HTMLMediaElement(%p)::suspend\n", this);

    switch (why)
    {
        case PageCache:
            stopWithoutDestroyingMediaPlayer();
            m_asyncEventQueue->suspend();
            setShouldBufferData(false);
            break;
        case PageWillBeSuspended:
        case JavaScriptDebuggerPaused:
        case WillDeferLoading:
            // Do nothing, we don't pause media playback in these cases.
            break;
    }
}

void HTMLMediaElement::resume()
{
    gMediaLog("HTMLMediaElement(%p)::resume\n", this);

    m_inActiveDocument = true;

    m_asyncEventQueue->resume();

    setShouldBufferData(true);

    setPausedInternal(false);

    if (m_error && m_error->code() == MediaError::MEDIA_ERR_ABORTED) {
        // Restart the load if it was aborted in the middle by moving the document to the page cache.
        // m_error is only left at MEDIA_ERR_ABORTED when the document becomes inactive (it is set to
        //  MEDIA_ERR_ABORTED while the abortEvent is being sent, but cleared immediately afterwards).
        // This behavior is not specified but it seems like a sensible thing to do.
        // As it is not safe to immedately start loading now, let's schedule a load.
    	scheduleDelayedAction(LoadMediaResource);
    }

    if (renderer())
        renderer()->updateFromElement();
}

bool HTMLMediaElement::virtualHasPendingActivity() const
{
    return (hasAudio() && isPlaying()) || m_asyncEventQueue->hasPendingEvents();
}

void HTMLMediaElement::mediaVolumeDidChange()
{
    gMediaLog("HTMLMediaElement(%p)::mediaVolumeDidChange\n", this);
    updateVolume();
}

void HTMLMediaElement::defaultEventHandler(Event* event)
{
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
	auto r = renderer();
    if (!r || !r->isWidget())
        return;

    Widget* widget = toRenderWidget(r)->widget();
    if (widget)
        widget->handleEvent(event);
#else
    HTMLElement::defaultEventHandler(event);
#endif
}

bool HTMLMediaElement::willRespondToMouseClickEvents()
{
#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    return true;
#else
    return HTMLElement::willRespondToMouseClickEvents();
#endif
}

#if ENABLE(PLUGIN_PROXY_FOR_VIDEO)

void HTMLMediaElement::ensureMediaPlayer()
{
    if (!m_player)
        createMediaPlayer();
}

void HTMLMediaElement::deliverNotification(MediaPlayerProxyNotificationType notification)
{
    if (notification == MediaPlayerNotificationPlayPauseButtonPressed) {
        togglePlayState();
        return;
    }

    if (m_player)
        m_player->deliverNotification(notification);
}

void HTMLMediaElement::setMediaPlayerProxy(WebMediaPlayerProxy* proxy)
{
    ensureMediaPlayer();
    m_player->setMediaPlayerProxy(proxy);
}

void HTMLMediaElement::getPluginProxyParams(KURL& url, Vector<String>& names, Vector<String>& values)
{
    RefPtr<HTMLMediaElement> protect(this); // selectNextSourceChild may fire 'beforeload', which can make arbitrary DOM mutations.

    Frame* frame = document().frame();

    if (isVideo()) {
        HTMLVideoElement* video = static_cast<HTMLVideoElement*>(this);
        KURL posterURL = video->posterImageURL();
        if (!posterURL.isEmpty() && frame && frame->loader()->willLoadMediaElementURL(posterURL)) {
            names.append("_media_element_poster_");
            values.append(posterURL.string());
        }
    }

    if (controls()) {
        names.append("_media_element_controls_");
        values.append("true");
    }

    url = src();
    if (!isSafeToLoadURL(url, Complain))
        url = selectNextSourceChild(0, 0, DoNothing);

    m_currentSrc = url;
    if (url.isValid() && frame && frame->loader()->willLoadMediaElementURL(url)) {
        names.append("_media_element_src_");
        values.append(m_currentSrc.string());
    }
}

void HTMLMediaElement::createMediaPlayerProxy()
{
    ensureMediaPlayer();

    if (m_proxyWidget || (inDocument() && !m_needWidgetUpdate))
        return;

    Frame* frame = document().frame();
    if (!frame)
        return;

    gMediaLog("HTMLMediaElement(%p)::createMediaPlayerProxy\n", this);

    KURL url;
    Vector<String> paramNames;
    Vector<String> paramValues;

    getPluginProxyParams(url, paramNames, paramValues);
    
    // Hang onto the proxy widget so it won't be destroyed if the plug-in is set to
    // display:none
    m_proxyWidget = frame->loader()->subframeLoader()->loadMediaPlayerProxyPlugin(this, url, paramNames, paramValues);
    if (m_proxyWidget)
        m_needWidgetUpdate = false;
}

void HTMLMediaElement::updateWidget(PluginCreationOption)
{
    mediaElement->setNeedWidgetUpdate(false);

    Vector<String> paramNames;
    Vector<String> paramValues;
    // FIXME: Rename kurl to something more sensible.
    KURL kurl;

    mediaElement->getPluginProxyParams(kurl, paramNames, paramValues);
    // FIXME: What if document().frame() is 0?
    SubframeLoader* loader = document().frame()->loader()->subframeLoader();
    loader->loadMediaPlayerProxyPlugin(mediaElement, kurl, paramNames, paramValues);
}

#endif // ENABLE(PLUGIN_PROXY_FOR_VIDEO)

bool HTMLMediaElement::isFullscreen() const
{
    if (m_isFullscreen)
        return true;
    
#if ENABLE(FULLSCREEN_API)
    if (document().webkitIsFullScreen() && document().webkitCurrentFullScreenElement() == this)
        return true;
#endif
    
    return false;
}

void HTMLMediaElement::enterFullscreen()
{
    gMediaLog("HTMLMediaElement(%p)::enterFullscreen\n", this);

#if ENABLE(FULLSCREEN_API)
    if (document().settings().fullScreenEnabled()) {
        document().requestFullScreenForElement(this, 0, Document::ExemptIFrameAllowFullScreenRequirement);
        return;
    }
#endif
    ASSERT(!m_isFullscreen);
    m_isFullscreen = true;
    if (hasMediaControls())
        mediaControls()->enteredFullscreen();
    if (document().page()) {
        document().page()->chrome()->client()->enterFullscreenForNode(this);
        scheduleEvent(eventNames().webkitbeginfullscreenEvent);
    }
}

void HTMLMediaElement::exitFullscreen()
{
    gMediaLog("HTMLMediaElement(%p)::exitFullscreen\n", this);

#if ENABLE(FULLSCREEN_API)
    if (document().settings().fullScreenEnabled()) {
        if (document().webkitIsFullScreen() && document().webkitCurrentFullScreenElement() == this)
            document().webkitCancelFullScreen();
        return;
    }
#endif
    ASSERT(m_isFullscreen);
    m_isFullscreen = false;
    if (hasMediaControls())
        mediaControls()->exitedFullscreen();
    if (document().page()) {
        if (document().page()->chrome()->requiresFullscreenForVideoPlayback())
            pauseInternal();
        document().page()->chrome()->client()->exitFullscreenForNode(this);
        scheduleEvent(eventNames().webkitendfullscreenEvent);
    }
}

void HTMLMediaElement::didBecomeFullscreenElement()
{
    if (hasMediaControls())
        mediaControls()->enteredFullscreen();
}

void HTMLMediaElement::willStopBeingFullscreenElement()
{
    if (hasMediaControls())
        mediaControls()->exitedFullscreen();
}

PlatformMedia HTMLMediaElement::platformMedia() const
{
    return m_player ? m_player->platformMedia() : noPlatformMedia();
}

#if USE(ACCELERATED_COMPOSITING)
PlatformLayer* HTMLMediaElement::platformLayer() const
{
    return m_player ? m_player->platformLayer() : 0;
}
#endif

bool HTMLMediaElement::hasClosedCaptions() const
{
    if (m_player && m_player->hasClosedCaptions())
        return true;

#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled() && m_textTracks)
    for (unsigned i = 0; i < m_textTracks->length(); ++i) {
        if (m_textTracks->item(i)->readinessState() == TextTrack::FailedToLoad)
            continue;

        if (m_textTracks->item(i)->kind() == TextTrack::captionsKeyword()
            || m_textTracks->item(i)->kind() == TextTrack::subtitlesKeyword())
            return true;
    }
#endif

    return false;
}

bool HTMLMediaElement::closedCaptionsVisible() const
{
    return m_closedCaptionsVisible;
}

#if ENABLE(VIDEO_TRACK)
void HTMLMediaElement::updateTextTrackDisplay()
{
    if (!hasMediaControls() && !createMediaControls())
        return;

    mediaControls()->updateTextTrackDisplay();
}
#endif

void HTMLMediaElement::setClosedCaptionsVisible(bool closedCaptionVisible)
{
    gMediaLog("HTMLMediaElement(%p)::setClosedCaptionsVisible(%s)\n", this, boolString(closedCaptionVisible));

    if (!m_player)
        return;

    m_closedCaptionsVisible = closedCaptionVisible;
    m_player->setClosedCaptionsVisible(closedCaptionVisible);

#if ENABLE(VIDEO_TRACK)
    if (RuntimeEnabledFeatures::webkitVideoTrackEnabled()) {
        m_disableCaptions = !m_closedCaptionsVisible;

        markCaptionAndSubtitleTracksAsUnconfigured();

        updateTextTrackDisplay();
    }
#else
    if (hasMediaControls())
        mediaControls()->changedClosedCaptionsVisibility();
#endif
}

void HTMLMediaElement::setWebkitClosedCaptionsVisible(bool visible)
{
    setClosedCaptionsVisible(visible);
}

bool HTMLMediaElement::webkitClosedCaptionsVisible() const
{
    return closedCaptionsVisible();
}


bool HTMLMediaElement::webkitHasClosedCaptions() const
{
    return hasClosedCaptions();
}

#if ENABLE(MEDIA_STATISTICS)
unsigned HTMLMediaElement::webkitAudioDecodedByteCount() const
{
    if (!m_player)
        return 0;
    return m_player->audioDecodedByteCount();
}

unsigned HTMLMediaElement::webkitVideoDecodedByteCount() const
{
    if (!m_player)
        return 0;
    return m_player->videoDecodedByteCount();
}
#endif

void HTMLMediaElement::mediaCanStart()
{
    gMediaLog("HTMLMediaElement(%p)::mediaCanStart\n", this);

    ASSERT(m_isWaitingUntilMediaCanStart);
    m_isWaitingUntilMediaCanStart = false;
    loadInternal();
}

bool HTMLMediaElement::isURLAttribute(const Attribute& attribute) const
{
    return attribute.name() == srcAttr || HTMLElement::isURLAttribute(attribute);
}

void HTMLMediaElement::setShouldDelayLoadEvent(bool shouldDelay)
{
    if (m_shouldDelayLoadEvent == shouldDelay)
        return;

    gMediaLog("HTMLMediaElement(%p)::setShouldDelayLoadEvent(%s)\n", this, boolString(shouldDelay));

#if !PLATFORM(ESPIAL)
    m_shouldDelayLoadEvent = shouldDelay;
    if (shouldDelay)
        document().incrementLoadEventDelayCount();
    else
        document().decrementLoadEventDelayCount();
#endif
}
    

void HTMLMediaElement::getSitesInMediaCache(Vector<String>& sites)
{
    MediaPlayer::getSitesInMediaCache(sites);
}

void HTMLMediaElement::clearMediaCache()
{
    MediaPlayer::clearMediaCache();
}

void HTMLMediaElement::clearMediaCacheForSite(const String& site)
{
    MediaPlayer::clearMediaCacheForSite(site);
}

void HTMLMediaElement::privateBrowsingStateDidChange()
{
    if (!m_player)
        return;

    bool privateMode = document().settings().privateBrowsingEnabled();
    gMediaLog("HTMLMediaElement(%p)::privateBrowsingStateDidChange(%s)\n", this, boolString(privateMode));
    m_player->setPrivateBrowsingMode(privateMode);
}

MediaControls* HTMLMediaElement::mediaControls() const
{
#if ENABLE(MEDIA_CONTROLS_SCRIPT)
    return nullptr;
#else
    RefPtr<ShadowRoot> root = userAgentShadowRoot();
    if (!root)
        return 0;

    return childrenOfType<MediaControls>(*root).first();
#endif
}

bool HTMLMediaElement::hasMediaControls() const
{
#if ENABLE(MEDIA_CONTROLS_SCRIPT)
    return false;
#else

    if (RefPtr<ShadowRoot> root = userAgentShadowRoot()) {
        Node* node = childrenOfType<MediaControls>(*root).first();
        ASSERT_WITH_SECURITY_IMPLICATION(!node || node->isMediaControls());
        return node;
    }

    return false;
#endif
}

bool HTMLMediaElement::createMediaControls()
{
    if (hasMediaControls())
        return true;

    RefPtr<MediaControls> mediaControls = MediaControls::create(&document());
    if (!mediaControls)
        return false;

    mediaControls->setMediaController(m_mediaController ? m_mediaController.get() : static_cast<MediaControllerInterface*>(this));
    mediaControls->reset();
    if (isFullscreen())
    	mediaControls->enteredFullscreen();

    ensureUserAgentShadowRoot().appendChild(*mediaControls, ASSERT_NO_EXCEPTION);

    if (!controls() || !inDocument())
    	mediaControls->hide();

    return true;
}

void HTMLMediaElement::configureMediaControls()
{
#if !ENABLE(PLUGIN_PROXY_FOR_VIDEO)
    if (!controls() || !inDocument()) {
        if (hasMediaControls())
            mediaControls()->hide();
        return;
    }

    if (!hasMediaControls() && !createMediaControls())
        return;

    mediaControls()->show();
#else
    if (!hasMediaControls())
        createMediaControls();

    if (m_player)
        m_player->setControls(controls());
#endif
}

#if ENABLE(VIDEO_TRACK)
void HTMLMediaElement::configureTextTrackDisplay()
{
    ASSERT(m_textTracks);

    bool haveVisibleTextTrack = false;
    for (unsigned i = 0; i < m_textTracks->length(); ++i) {
        if (m_textTracks->item(i)->mode() == TextTrack::showingKeyword()) {
            haveVisibleTextTrack = true;
            break;
        }
    }

    if (m_haveVisibleTextTrack == haveVisibleTextTrack)
        return;
    m_haveVisibleTextTrack = haveVisibleTextTrack;
    m_closedCaptionsVisible = m_haveVisibleTextTrack;

    if (!m_haveVisibleTextTrack && !hasMediaControls())
        return;
    if (!hasMediaControls() && !createMediaControls())
        return;

    mediaControls()->changedClosedCaptionsVisibility();

	if (RuntimeEnabledFeatures::webkitVideoTrackEnabled())
		updateTextTrackDisplay();
}

void HTMLMediaElement::captionPreferencesChanged()
{
    if (!isVideo())
        return;

    markCaptionAndSubtitleTracksAsUnconfigured();
}

void HTMLMediaElement::markCaptionAndSubtitleTracksAsUnconfigured()
{
    // Mark all track elements as not "configured" so that configureTextTracks()
    // will reconsider which tracks to display in light of new user preferences
    // (e.g. default tracks should not be displayed if the user has turned off
    // captions and non-default tracks should be displayed based on language
    // preferences if the user has turned captions on).
    for (RefPtr<Node> node = firstChild(); node; node = node->nextSibling()) {
        if (!node->hasTagName(trackTag))
            continue;

        HTMLTrackElement* trackElement = static_cast<HTMLTrackElement*>(node.get());
        RefPtr<TextTrack> textTrack = trackElement->track();
        if (!textTrack)
            continue;

        String kind = textTrack->kind();

        if (kind == TextTrack::subtitlesKeyword() || kind == TextTrack::captionsKeyword())
        	textTrack->setHasBeenConfigured(false);
    }
    configureTextTracks();
}

#endif

void HTMLMediaElement::createMediaPlayer()
{
#if ENABLE(WEB_AUDIO)
    if (m_audioSourceNode)
        m_audioSourceNode->lock();
#endif
        
#if ENABLE(MEDIA_SOURCE)
    if (m_mediaSource)
        m_mediaSource->detachFromElement(*this);
#endif

#if ENABLE(MEDIA_STREAM)
    m_mediaStreamSrcObject = nullptr;
#endif

    if(!m_player)
    	m_player = MediaPlayer::create(this);

#if ENABLE(WEB_AUDIO)
    if (m_audioSourceNode) {
        // When creating the player, make sure its AudioSourceProvider knows about the MediaElementAudioSourceNode.
        if (audioSourceProvider())
            audioSourceProvider()->setClient(m_audioSourceNode);

        m_audioSourceNode->unlock();
    }
#endif
}

#if ENABLE(WEB_AUDIO)
void HTMLMediaElement::setAudioSourceNode(MediaElementAudioSourceNode* sourceNode)
{
    m_audioSourceNode = sourceNode;

    if (audioSourceProvider())
        audioSourceProvider()->setClient(m_audioSourceNode);
}

AudioSourceProvider* HTMLMediaElement::audioSourceProvider()
{
    if (m_player)
        return m_player->audioSourceProvider();

    return 0;
}
#endif

#if ENABLE(MICRODATA)
String HTMLMediaElement::itemValueText() const
{
    return getURLAttribute(srcAttr);
}

void HTMLMediaElement::setItemValueText(const String& value, ExceptionCode&)
{
    setAttribute(srcAttr, value);
}
#endif

const String& HTMLMediaElement::mediaGroup() const
{
    return m_mediaGroup;
}

void HTMLMediaElement::setMediaGroup(const String& group)
{
    if (m_mediaGroup == group)
        return;

    gMediaLog("HTMLMediaElement(%p)::setMediaGroup(%s)\n", this, group.utf8().data());

    m_mediaGroup = group;

    // When a media element is created with a mediagroup attribute, and when a media element's mediagroup 
    // attribute is set, changed, or removed, the user agent must run the following steps:
    // 1. Let m [this] be the media element in question.
    // 2. Let m have no current media controller, if it currently has one.
    setController(nullptr);

    // 3. If m's mediagroup attribute is being removed, then abort these steps.
    if (group.isEmpty())
        return;

    // 4. If there is another media element whose Document is the same as m's Document (even if one or both
    // of these elements are not actually in the Document), 
    HashSet<HTMLMediaElement*> elements = documentToElementSetMap().get(&document());
    for (HashSet<HTMLMediaElement*>::iterator i = elements.begin(); i != elements.end(); ++i) {
        if (*i == this)
            continue;

        // and which also has a mediagroup attribute, and whose mediagroup attribute has the same value as
        // the new value of m's mediagroup attribute,        
        if ((*i)->mediaGroup() == group) {
            //  then let controller be that media element's current media controller.
            setController((*i)->controller());
            return;
        }
    }

    // Otherwise, let controller be a newly created MediaController.
    setController(MediaController::create(Node::scriptExecutionContext()));
}

MediaController* HTMLMediaElement::controller() const
{
	if(document().settings().mediaControllerEnabled())
		return m_mediaController.get();
	return 0;
}

void HTMLMediaElement::setController(PassRefPtr<MediaController> controller)
{
	if (m_mediaController)
		m_mediaController->removeMediaElement(this);

	m_mediaController = controller;

	if (m_mediaController)
		m_mediaController->addMediaElement(this);

    if (hasMediaControls())
        mediaControls()->setMediaController(m_mediaController ? m_mediaController.get() : static_cast<MediaControllerInterface*>(this));
}

void HTMLMediaElement::setControllerForBindings(MediaController* controller)
{
    // 4.8.10.11.2 Media controllers: controller attribute.
    // On setting, it must first remove the element's mediagroup attribute, if any,
    setMediaGroup(String());
    // and then set the current media controller to the given value.
    setController(controller);
}

void HTMLMediaElement::updateMediaController()
{
    if (m_mediaController)
        m_mediaController->reportControllerState();
}

void HTMLMediaElement::dispatchEvent(PassRefPtr<Event> event)
{
    bool isCanPlayEvent;

    isCanPlayEvent = (event->type() == eventNames().canplayEvent);

    if (isCanPlayEvent)
        m_dispatchingCanPlayEvent = true;

    if(event->type() == eventNames().timeupdateEvent){
        double now = monotonicallyIncreasingTime();
        double timedelta = now - m_clockTimeAtLastUpdateEvent;

        if(timedelta >= minTimeupdateEventFrequency){
        	m_clockTimeAtLastUpdateEvent = now;
	    	HTMLElement::dispatchEvent(event);
        }
        else{
        	if(m_playbackProgressTimer.isActive())
        		m_playbackProgressTimer.start(maxTimeupdateEventFrequency - timedelta, maxTimeupdateEventFrequency);
        }
    }
    else{
    	if(event->type() != eventNames().progressEvent){
    		gMediaLog("HTMLMediaElement(%p)::dispatchEvent '%s'\n", this, event->type().string().ascii().data());
    	}

    	HTMLElement::dispatchEvent(event);
    }

    if (isCanPlayEvent)
        m_dispatchingCanPlayEvent = false;
}

bool HTMLMediaElement::isBlocked() const
{
    // A media element is a blocked media element if its readyState attribute is in the
    // HAVE_NOTHING state, the HAVE_METADATA state, or the HAVE_CURRENT_DATA state,
    if (m_readyState <= HAVE_CURRENT_DATA)
        return true;

    // or if the element has paused for user interaction.
    return pausedForUserInteraction();
}

bool HTMLMediaElement::isBlockedOnMediaController() const
{
    if (!m_mediaController)
        return false;

    // A media element is blocked on its media controller if the MediaController is a blocked 
    // media controller,
    if (m_mediaController->isBlocked())
        return true;

    // or if its media controller position is either before the media resource's earliest possible 
    // position relative to the MediaController's timeline or after the end of the media resource 
    // relative to the MediaController's timeline.
    double mediaControllerPosition = m_mediaController->currentTime();
    if (mediaControllerPosition < 0 || mediaControllerPosition > duration())
        return true;

    return false;
}

void HTMLMediaElement::prepareMediaFragmentURI()
{
    MediaFragmentURIParser fragmentParser(m_currentSrc);
    MediaTime dur = durationMediaTime();
    
    MediaTime start = fragmentParser.startTime();
    if (start.isValid() && start > MediaTime::zeroTime()) {
        m_fragmentStartTime = start;
        if (m_fragmentStartTime > dur)
            m_fragmentStartTime = dur;
    } else
        m_fragmentStartTime = MediaTime::invalidTime();
    
    MediaTime end = fragmentParser.endTime();
    if (end.isValid() && end > MediaTime::zeroTime() && (!m_fragmentStartTime.isValid() || end > m_fragmentStartTime)) {
        m_fragmentEndTime = end;
        if (m_fragmentEndTime > dur)
            m_fragmentEndTime = dur;
    } else
        m_fragmentEndTime = MediaTime::invalidTime();
    
    if (m_fragmentStartTime.isValid() && m_readyState < HAVE_FUTURE_DATA)
        prepareToPlay();
}

void HTMLMediaElement::applyMediaFragmentURI()
{
	if(!m_player)
		return;

    if (m_fragmentStartTime.isValid()) {
        m_sentEndEvent = false;

        if(!m_player->supportsFragmentStartTime())
        	seekInternal(m_fragmentStartTime);
        else
            gMediaLog("HTMLMediaElement(%p)::applyMediaFragmentURI(%s) already passed to player when loading.\n", this, toString(m_fragmentStartTime).utf8().data());
    }
}

#if PLATFORM(MAC)
void HTMLMediaElement::updateDisableSleep()
{
    if (!shouldDisableSleep() && m_sleepDisabler)
        m_sleepDisabler = nullptr;
    else if (shouldDisableSleep() && !m_sleepDisabler)
        m_sleepDisabler = DisplaySleepDisabler::create("com.apple.WebCore: HTMLMediaElement playback");
}

bool HTMLMediaElement::shouldDisableSleep() const
{
    return m_player && !m_player->paused() && hasVideo() && hasAudio() && !loop();
}
#endif

String HTMLMediaElement::mediaPlayerReferrer() const
{
    Frame* frame = document().frame();
    if (!frame)
        return String();

    return SecurityPolicy::generateReferrerHeader(document().referrerPolicy(), m_currentSrc, frame->loader()->outgoingReferrer());
}

String HTMLMediaElement::mediaPlayerUserAgent() const
{
    Frame* frame = document().frame();
    if (!frame)
        return String();

    return frame->loader()->userAgent(m_currentSrc);

}

MediaPlayerClient::CORSMode HTMLMediaElement::mediaPlayerCORSMode() const
{
    if (!hasAttributeWithoutSynchronization(HTMLNames::crossoriginAttr))
        return Unspecified;
    if (equalLettersIgnoringASCIICase(attributeWithoutSynchronization(HTMLNames::crossoriginAttr), "use-credentials"))
        return UseCredentials;
    return Anonymous;
}

bool HTMLMediaElement::mediaPlayerNeedsSiteSpecificHacks() const
{
    return document().settings().needsSiteSpecificQuirks();
}

String HTMLMediaElement::mediaPlayerDocumentHost() const
{
    return document().url().host().toString();
}

void HTMLMediaElement::removeBehaviorsRestrictionsAfterFirstUserGesture()
{
    m_restrictions = NoRestrictions;
}

#if ENABLE(MEDIA_SOURCE)
RefPtr<VideoPlaybackQuality> HTMLMediaElement::getVideoPlaybackQuality()
{
	DOMWindow* domWindow = document().domWindow();
	double timestamp = domWindow ? domWindow->nowTimestamp().milliseconds() : 0;

    if (!m_player)
        return VideoPlaybackQuality::create(timestamp, 0, 0, 0, 0);

    return VideoPlaybackQuality::create(timestamp,
        m_droppedVideoFrames + m_player->totalVideoFrames(),
        m_droppedVideoFrames + m_player->droppedVideoFrames(),
        m_player->corruptedVideoFrames(),
        m_player->totalFrameDelay().toDouble());
}
#endif

void HTMLMediaElement::setShouldBufferData(bool shouldBuffer)
{
#if 0
    if (m_player)
        return m_player->setShouldBufferData(shouldBuffer);
#endif
}

}
#endif
