Initial implementation of AudioTrack, AudioTrackList, VideoTrack, and VideoTrackList.

Source/core/html/HTMLMediaElement.cpp

Index: Source/core/html/HTMLMediaElement.cpp
diff --git a/Source/core/html/HTMLMediaElement.cpp b/Source/core/html/HTMLMediaElement.cpp
index cec3e8f28f9a7b68d9fdd7a07390770f9473bf65..c0269508f989d9d66968ca6cfa968e0b0e3dbb9d 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -54,9 +54,13 @@
 #include "core/html/MediaKeyEvent.h"
 #include "core/html/TimeRanges.h"
 #include "core/html/shadow/MediaControls.h"
+#include "core/html/track/AudioTrack.h"
+#include "core/html/track/AudioTrackList.h"
 #include "core/html/track/InbandTextTrack.h"
 #include "core/html/track/TextTrackCueList.h"
 #include "core/html/track/TextTrackList.h"
+#include "core/html/track/VideoTrack.h"
+#include "core/html/track/VideoTrackList.h"
 #include "core/loader/FrameLoader.h"
 #include "core/rendering/RenderLayerCompositor.h"
 #include "core/rendering/RenderVideo.h"
@@ -302,6 +306,8 @@ HTMLMediaElement::HTMLMediaElement(const QualifiedName& tagName, Document& docum
     , m_haveVisibleTextTrack(false)
     , m_processingPreferenceChange(false)
     , m_lastTextTrackUpdateTime(-1)
+    , m_audioTracks(nullptr)
+    , m_videoTracks(nullptr)
     , m_textTracks(nullptr)
     , m_ignoreTrackDisplayUpdate(0)
 #if ENABLE(WEB_AUDIO)
@@ -335,12 +341,12 @@ HTMLMediaElement::~HTMLMediaElement()
     m_asyncEventQueue->close();
 
     setShouldDelayLoadEvent(false);
+    if (m_audioTracks)
+        m_audioTracks->clearOwner();
+    if (m_videoTracks)
+        m_videoTracks->clearOwner();
     if (m_textTracks)
-        m_textTracks->clearOwner();
-    if (m_textTracks) {
-        for (unsigned i = 0; i < m_textTracks->length(); ++i)
-            m_textTracks->item(i)->clearClient();
-    }
+        m_textTracks->clearOwnerAndClients();
 
     if (m_mediaController) {
         m_mediaController->removeMediaElement(this);
@@ -663,14 +669,38 @@ void HTMLMediaElement::prepareForLoad()
 
     // 4 - If the media element's networkState is not set to NETWORK_EMPTY, then run these substeps
     if (m_networkState != NETWORK_EMPTY) {
+        // 4.1 - Queue a task to fire a simple event named emptied at the media element.
+        scheduleEvent(EventTypeNames::emptied);
+
+        // 4.2 - If a fetching process is in progress for the media element, the user agent should stop it.
         m_networkState = NETWORK_EMPTY;
+
+        // 4.3 - Forget the media element's media-resource-specific tracks.
+        forgetResourceSpecificTracks();
+
+        // 4.4 - If readyState is not set to HAVE_NOTHING, then set it to that state.
         m_readyState = HAVE_NOTHING;
         m_readyStateMaximum = HAVE_NOTHING;
-        refreshCachedTime();
+
+        // 4.5 - If the paused attribute is false, then set it to true.
         m_paused = true;
+
+        // 4.6 - If seeking is true, set it to false.
         m_seeking = false;
+
+        // 4.7 - Set the current playback position to 0.
+        //       Set the official playback position to 0.
+        //       If this changed the official playback position, then queue a task to fire a simple event named timeupdate at the media element.
+
+        // 4.8 - Set the initial playback position to 0.
+        // FIXME: Make this less subtle. The position only becomes 0 because of the createMediaPlayer() call
+        // above.
+        refreshCachedTime();
         invalidateCachedTime();
-        scheduleEvent(EventTypeNames::emptied);
+
+        // 4.9 - Set the timeline offset to Not-a-Number (NaN).
+        // 4.10 - Update the duration attribute to Not-a-Number (NaN).
+
         updateMediaController();
         if (RuntimeEnabledFeatures::videoTrackEnabled())
             updateActiveTextTrackCues(0);
@@ -694,6 +724,9 @@ void HTMLMediaElement::prepareForLoad()
     // 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 = 0;
     m_duration = numeric_limits<double>::quiet_NaN();
 
@@ -1364,6 +1397,7 @@ void HTMLMediaElement::noneSupported()
     m_error = MediaError::create(MediaError::MEDIA_ERR_SRC_NOT_SUPPORTED);
 
     // 6.2 - Forget the media element's media-resource-specific text tracks.
+    forgetResourceSpecificTracks();
 
     // 6.3 - Set the element's networkState attribute to the NETWORK_NO_SOURCE value.
     m_networkState = NETWORK_NO_SOURCE;
@@ -1437,12 +1471,18 @@ void HTMLMediaElement::mediaLoadingFailed(MediaPlayer::NetworkState error)
     // 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) {
-
+        // resource selection algorithm
+        // Step 9.Otherwise.9 - Failed with elements: Queue a task, using the DOM manipulation task source, to fire a simple event named error at the candidate element.
         if (m_currentSourceNode)
             m_currentSourceNode->scheduleErrorEvent();
         else
             WTF_LOG(Media, "HTMLMediaElement::setNetworkState - error event not sent, <source> was removed");
 
+        // 9.Otherwise.10 - Asynchronously await a stable state. The synchronous section consists of all the remaining steps of this algorithm until the algorithm says the synchronous section has ended. (Steps in synchronous sections are marked with ⌛.)
+
+        // 9.Otherwise.11 Forget the media element's media-resource-specific tracks.
+        forgetResourceSpecificTracks();
+
         if (havePotentialSourceChild()) {
             WTF_LOG(Media, "HTMLMediaElement::setNetworkState - scheduling next <source>");
             scheduleNextSourceChild();
@@ -1574,7 +1614,12 @@ void HTMLMediaElement::setReadyState(MediaPlayer::ReadyState state)
     }
 
     if (m_readyState >= HAVE_METADATA && oldState < HAVE_METADATA) {
+        createPlaceholderTracksIfNecessary();
+
         prepareMediaFragmentURI();
+
+        selectInitialTracksIfNecessary();
+
         scheduleEvent(EventTypeNames::durationchange);
         if (isVideo())
             scheduleEvent(EventTypeNames::resize);
@@ -2452,7 +2497,99 @@ bool HTMLMediaElement::canPlay() const
     return paused() || ended() || m_readyState < HAVE_METADATA;
 }
 
-void HTMLMediaElement::mediaPlayerDidAddTrack(WebInbandTextTrack* webTrack)
+AudioTrackList* HTMLMediaElement::audioTracks()
+{
+    ASSERT(RuntimeEnabledFeatures::audioVideoTracksEnabled());
+
+    if (!m_audioTracks)
+        m_audioTracks = AudioTrackList::create(this);
+
+    return m_audioTracks.get();
+}
+
+void HTMLMediaElement::didEnabledAudioTrackChange(const AtomicString& audioTrackID, bool enabled)
+{
+    WTF_LOG(Media, "HTMLMediaElement::didEnabledAudioTrackChange('%s', %d)", audioTrackID.ascii().data(), enabled);
+    ASSERT(RuntimeEnabledFeatures::audioVideoTracksEnabled());
+    ASSERT(!audioTrackID.isEmpty());
+
+    if (webMediaPlayer())
+        webMediaPlayer()->enabledAudioTrackChange(audioTrackID, enabled);
+}
+
+VideoTrackList* HTMLMediaElement::videoTracks()
+{
+    ASSERT(RuntimeEnabledFeatures::audioVideoTracksEnabled());
+
+    if (!m_videoTracks)
+        m_videoTracks = VideoTrackList::create(this);
+
+    return m_videoTracks.get();
+}
+
+void HTMLMediaElement::didSelectedVideoTrackChange(const AtomicString& unselectedTrackID, const AtomicString& selectedTrackID)
+{
+    WTF_LOG(Media, "HTMLMediaElement::didSelectedVideoTrackChange('%s', '%s')", unselectedTrackID.ascii().data(), selectedTrackID.ascii().data());
+    ASSERT(RuntimeEnabledFeatures::audioVideoTracksEnabled());
+    ASSERT(!unselectedTrackID.isEmpty() || !selectedTrackID.isEmpty());
+
+    if (webMediaPlayer())
+        webMediaPlayer()->selectedVideoTrackChange(unselectedTrackID, selectedTrackID);
+}
+
+void HTMLMediaElement::mediaPlayerDidAddVideoTrack(const AtomicString& id, const AtomicString& kind, const AtomicString& label, const AtomicString& language, bool selected)
+{
+    WTF_LOG(Media, "HTMLMediaElement::mediaPlayerDidAddVideoTrack('%s', '%s', '%s', '%s', %d)",
+        id.ascii().data(), kind.ascii().data(), label.ascii().data(), language.ascii().data(), selected);
+    ASSERT(!id.isEmpty());
+
+    RefPtr<VideoTrack> videoTrack = VideoTrack::create(videoTracks(), id, kind, label, language);
+    videoTracks()->add(videoTrack.get());
+
+    if (selected)
+        videoTrack->setSelected(true);
+}
+
+void HTMLMediaElement::mediaPlayerDidRemoveVideoTrack(const AtomicString& id)
+{
+    WTF_LOG(Media, "HTMLMediaElement::mediaPlayerDidRevmoeVideoTrack('%s')", id.ascii().data());
+    ASSERT(!id.isEmpty());
+
+    if (!RuntimeEnabledFeatures::audioVideoTracksEnabled())
+        return;
+
+    videoTracks()->remove(id);
+}
+
+void HTMLMediaElement::mediaPlayerDidAddAudioTrack(const AtomicString& id, const AtomicString& kind, const AtomicString& label, const AtomicString& language, bool enabled)
+{
+    WTF_LOG(Media, "HTMLMediaElement::mediaPlayerDidAddAudioTrack('%s', '%s', '%s', '%s', %d)",
+        id.ascii().data(), kind.ascii().data(), label.ascii().data(), language.ascii().data(), enabled);
+    ASSERT(!id.isEmpty());
+
+    if (!RuntimeEnabledFeatures::audioVideoTracksEnabled())
+        return;
+
+    AtomicString kindString;
+    RefPtr<AudioTrack> audioTrack = AudioTrack::create(audioTracks(), id, kind, label, language);
+    audioTracks()->add(audioTrack.get());
+
+    if (enabled)
+        audioTrack->setEnabled(true);
+}
+
+void HTMLMediaElement::mediaPlayerDidRemoveAudioTrack(const AtomicString& id)
+{
+    WTF_LOG(Media, "HTMLMediaElement::mediaPlayerDidRevmoeAudioTrack('%s')", id.ascii().data());
+    ASSERT(!id.isEmpty());
+
+    if (!RuntimeEnabledFeatures::audioVideoTracksEnabled())
+        return;
+
+    audioTracks()->remove(id);
+}
+
+void HTMLMediaElement::mediaPlayerDidAddTextTrack(WebInbandTextTrack* webTrack)
 {
     if (!RuntimeEnabledFeatures::videoTrackEnabled())
         return;
@@ -2484,10 +2621,10 @@ void HTMLMediaElement::mediaPlayerDidAddTrack(WebInbandTextTrack* webTrack)
     // 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.
-    addTrack(textTrack.get());
+    addTextTrack(textTrack.get());
 }
 
-void HTMLMediaElement::mediaPlayerDidRemoveTrack(WebInbandTextTrack* webTrack)
+void HTMLMediaElement::mediaPlayerDidRemoveTextTrack(WebInbandTextTrack* webTrack)
 {
     if (!RuntimeEnabledFeatures::videoTrackEnabled())
         return;
@@ -2501,7 +2638,7 @@ void HTMLMediaElement::mediaPlayerDidRemoveTrack(WebInbandTextTrack* webTrack)
     if (!textTrack)
         return;
 
-    removeTrack(textTrack.get());
+    removeTextTrack(textTrack.get(), true);
 }
 
 void HTMLMediaElement::closeCaptionTracksChanged()
@@ -2510,36 +2647,44 @@ void HTMLMediaElement::closeCaptionTracksChanged()
         mediaControls()->closedCaptionTracksChanged();
 }
 
-void HTMLMediaElement::addTrack(TextTrack* track)
+void HTMLMediaElement::addTextTrack(TextTrack* track)
 {
     textTracks()->append(track);
 
     closeCaptionTracksChanged();
 }
 
-void HTMLMediaElement::removeTrack(TextTrack* track)
+void HTMLMediaElement::removeTextTrack(TextTrack* track, bool fireRemoveTrackEvent)
 {
     TrackDisplayUpdateScope scope(this);
     TextTrackCueList* cues = track->cues();
     if (cues)
         textTrackRemoveCues(track, cues);
-    m_textTracks->remove(track);
+    m_textTracks->remove(track, fireRemoveTrackEvent);
 
     closeCaptionTracksChanged();
 }
 
-void HTMLMediaElement::removeAllInbandTracks()
+void HTMLMediaElement::forgetResourceSpecificTracks()
 {
-    if (!m_textTracks)
-        return;
-
-    TrackDisplayUpdateScope scope(this);
-    for (int i = m_textTracks->length() - 1; i >= 0; --i) {
-        TextTrack* track = m_textTracks->item(i);
+    // Implements the "forget the media element's media-resource-specific tracks" algorithm.
+    // The order is explicitly specified as text, then audio, and finally video. Also
+    // 'removetrack' events should not be fired.
+    if (m_textTracks) {
+        TrackDisplayUpdateScope scope(this);
+        for (int i = m_textTracks->length() - 1; i >= 0; --i) {
+            TextTrack* track = m_textTracks->item(i);
 
-        if (track->trackType() == TextTrack::InBand)
-            removeTrack(track);
+            if (track->trackType() == TextTrack::InBand)
+                removeTextTrack(track, false);
+        }
     }
+
+    if (m_audioTracks)
+        m_audioTracks->removeAll();
+
+    if (m_videoTracks)
+        m_videoTracks->removeAll();
 }
 
 PassRefPtr<TextTrack> HTMLMediaElement::addTextTrack(const AtomicString& kind, const AtomicString& label, const AtomicString& language, ExceptionState& exceptionState)
@@ -2567,7 +2712,7 @@ PassRefPtr<TextTrack> HTMLMediaElement::addTextTrack(const AtomicString& kind, c
     // first append the track to the text track list.
 
     // 6. Add the new text track to the media element's list of text tracks.
-    addTrack(textTrack.get());
+    addTextTrack(textTrack.get());
 
     // ... its text track readiness state to the text track loaded state ...
     textTrack->setReadinessState(TextTrack::Loaded);
@@ -2603,7 +2748,7 @@ void HTMLMediaElement::didAddTrack(HTMLTrackElement* trackElement)
     if (!textTrack)
         return;
 
-    addTrack(textTrack.get());
+    addTextTrack(textTrack.get());
 
     // Do not schedule the track loading until parsing finishes so we don't start before all tracks
     // in the markup have been added.
@@ -2641,7 +2786,7 @@ void HTMLMediaElement::didRemoveTrack(HTMLTrackElement* trackElement)
     // 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.
-    removeTrack(textTrack.get());
+    removeTextTrack(textTrack.get(), true);
 
     size_t index = m_textTracksWhenResourceSelectionBegan.find(textTrack.get());
     if (index != kNotFound)
@@ -3394,7 +3539,7 @@ void HTMLMediaElement::clearMediaPlayerAndAudioSourceProviderClient()
 
 void HTMLMediaElement::clearMediaPlayer(int flags)
 {
-    removeAllInbandTracks();
+    forgetResourceSpecificTracks();
 
     closeMediaSource();
 
@@ -3861,6 +4006,8 @@ void HTMLMediaElement::prepareMediaFragmentURI()
     } else
         m_fragmentEndTime = MediaPlayer::invalidTime();
 
+    // FIXME: Add support for selecting tracks by ID with the Media Fragments track dimension.
+
     if (m_fragmentStartTime != MediaPlayer::invalidTime() && m_readyState < HAVE_FUTURE_DATA)
         prepareToPlay();
 }
@@ -3923,4 +4070,32 @@ bool HTMLMediaElement::isInteractiveContent() const
     return fastHasAttribute(controlsAttr);
 }
 
+void HTMLMediaElement::createPlaceholderTracksIfNecessary()
+{
+    if (!RuntimeEnabledFeatures::audioVideoTracksEnabled())
+        return;
+
+    // Create a placeholder audio track if |m_player| says it has audio but it didn't explicitly announce the tracks.
+    if (m_player->hasAudio() && !audioTracks()->length())
+        mediaPlayerDidAddAudioTrack("audio", AudioTrack::mainKeyword(), "Audio Track", "", true);
+
+    // Create a placeholder video track if |m_player| says it has video but it didn't explicitly announce the tracks.
+    if (m_player->hasVideo() && !videoTracks()->length())
+        mediaPlayerDidAddVideoTrack("video", VideoTrack::mainKeyword(), "Video Track", "", true);
+}
+
+void HTMLMediaElement::selectInitialTracksIfNecessary()
+{
+    if (!RuntimeEnabledFeatures::audioVideoTracksEnabled())
+        return;
+
+    // Enable the first audio track if an audio track hasn't been enabled yet.
+    if (audioTracks()->length() > 0 && !audioTracks()->hasEnabledTrack())
+        audioTracks()->anonymousIndexedGetter(0)->setEnabled(true);
+
+    // Select the first video track if a video track hasn't been selected yet.
+    if (videoTracks()->length() > 0 && videoTracks()->selectedIndex() == -1)
+        videoTracks()->anonymousIndexedGetter(0)->setSelected(true);
+}
+
 }