Generate and assign media track ids in demuxers.

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index ed596d00d9df66b3052914fec0e6c9c47b0352e2..5ccc612da789dd57985b0add97ef7b1cf0729c66 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -2393,7 +2393,7 @@ AudioTrackList& HTMLMediaElement::audioTracks()
 
 void HTMLMediaElement::audioTrackChanged(WebMediaPlayer::TrackId trackId, bool enabled)
 {
-    DVLOG(MEDIA_LOG_LEVEL) << "audioTrackChanged(" << (void*)this << ") trackId= " << trackId << " enabled=" << boolString(enabled);
+    DVLOG(MEDIA_LOG_LEVEL) << "audioTrackChanged(" << (void*)this << ") trackId= " << (String)trackId << " enabled=" << boolString(enabled);

[chcunningham, 2016/06/13 19:32:12]

Track Id is a string now right? is this needed? If so, static_cast?

[servolk, 2016/06/13 22:00:16]

Track id is a blink::WebString, and surprisingly blink::WebString doesn't
support operator<< and there's no implicit conversion from blink::WebString into
WTF::String. But blink::WebString has a conversion operator that converts into
WTF::String, so we need to be more explicit here. To make it look better I guess
we could construct a String out of track id here.

     DCHECK(RuntimeEnabledFeatures::audioVideoTracksEnabled());
 
     audioTracks().scheduleChangeEvent();
@@ -2423,7 +2423,7 @@ WebMediaPlayer::TrackId HTMLMediaElement::addAudioTrack(const WebString& id, Web
         << "', '" << (String)label << "', '" << (String)language << "', " << boolString(enabled) << ")";
 
     if (!RuntimeEnabledFeatures::audioVideoTracksEnabled())
-        return 0;
+        return blink::WebMediaPlayer::TrackId();
 
     AudioTrack* audioTrack = AudioTrack::create(id, kindString, label, language, enabled);
     audioTracks().add(audioTrack);
@@ -2449,7 +2449,7 @@ VideoTrackList& HTMLMediaElement::videoTracks()
 
 void HTMLMediaElement::selectedVideoTrackChanged(WebMediaPlayer::TrackId* selectedTrackId)
 {
-    DVLOG(MEDIA_LOG_LEVEL) << "selectedVideoTrackChanged(" << (void*)this << ") selectedTrackId=" << (selectedTrackId ? String::format("%u", *selectedTrackId) : "none");
+    DVLOG(MEDIA_LOG_LEVEL) << "selectedVideoTrackChanged(" << (void*)this << ") selectedTrackId=" << (selectedTrackId ? ((String)*selectedTrackId) : "none");
     DCHECK(RuntimeEnabledFeatures::audioVideoTracksEnabled());
 
     if (selectedTrackId)
@@ -2467,7 +2467,7 @@ WebMediaPlayer::TrackId HTMLMediaElement::addVideoTrack(const WebString& id, Web
         << "', '" << (String)label << "', '" << (String)language << "', " << boolString(selected) << ")";
 
     if (!RuntimeEnabledFeatures::audioVideoTracksEnabled())
-        return 0;
+        return blink::WebMediaPlayer::TrackId();
 
     // If another track was selected (potentially by the user), leave it selected.
     if (selected && videoTracks().selectedIndex() != -1)