Deliver change notifications to SourceBuffer track lists.

third_party/WebKit/Source/modules/mediasource/MediaSource.cpp

Index: third_party/WebKit/Source/modules/mediasource/MediaSource.cpp
diff --git a/third_party/WebKit/Source/modules/mediasource/MediaSource.cpp b/third_party/WebKit/Source/modules/mediasource/MediaSource.cpp
index e48dfd717a1b6cc1e55bdec28fe04bee0488aa5b..71124d30caacff479d47b42f0f297a129b9f6946 100644
--- a/third_party/WebKit/Source/modules/mediasource/MediaSource.cpp
+++ b/third_party/WebKit/Source/modules/mediasource/MediaSource.cpp
@@ -39,7 +39,10 @@
 #include "core/frame/Deprecation.h"
 #include "core/frame/UseCounter.h"
 #include "core/html/HTMLMediaElement.h"
+#include "core/html/track/AudioTrackList.h"
+#include "core/html/track/VideoTrackList.h"
 #include "modules/mediasource/MediaSourceRegistry.h"
+#include "modules/mediasource/SourceBufferTrackBaseSupplement.h"
 #include "platform/ContentType.h"
 #include "platform/MIMETypeRegistry.h"
 #include "platform/RuntimeEnabledFeatures.h"
@@ -416,6 +419,18 @@ TimeRanges* MediaSource::seekable() const
     return TimeRanges::create(0, sourceDuration);
 }
 
+void MediaSource::onTrackChanged(TrackBase* track)
+{
+    SourceBuffer* sourceBuffer = SourceBufferTrackBaseSupplement::sourceBuffer(*track);
+    if (sourceBuffer) {
+        if (track->type() == WebMediaPlayer::AudioTrack) {
+            sourceBuffer->audioTracks().scheduleChangeEvent();
+        } else if (track->type() == WebMediaPlayer::VideoTrack) {
+            sourceBuffer->videoTracks().scheduleChangeEvent();
+        }
+    }
+}
+
 void MediaSource::setDuration(double duration, ExceptionState& exceptionState)
 {
     // 2.1 http://www.w3.org/TR/media-source/#widl-MediaSource-duration