Create CanvasCaptureMediaStreamTrack in a regular MediaStream

content/public/renderer/media_stream_api.cc

Index: content/public/renderer/media_stream_api.cc
diff --git a/content/public/renderer/media_stream_api.cc b/content/public/renderer/media_stream_api.cc
index 5908c99690751894b0663c07b039da1a3a4fb26b..2c2cea3de4b8ec8ea9195e5fb4a523a6d0b9639c 100644
--- a/content/public/renderer/media_stream_api.cc
+++ b/content/public/renderer/media_stream_api.cc
@@ -14,6 +14,7 @@
 #include "content/renderer/render_thread_impl.h"
 #include "third_party/WebKit/public/platform/WebMediaStream.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/web/WebMediaStreamRegistry.h"
 #include "url/gurl.h"
@@ -129,4 +130,27 @@ bool AddAudioTrackToMediaStream(
   return true;
 }
 
+bool AddVideoCapturerSourceToVideoTrack(

[perkj_chrome, 2015/12/08 09:05:06]

This feel like a special case where we create a source after the track. So I
would just put this in CanvasCaptureHandler.

[emircan, 2015/12/08 19:28:01]

Done.

+    scoped_ptr<media::VideoCapturerSource> source,
+    bool is_remote,
+    bool is_readonly,
+    blink::WebMediaStreamTrack* web_track) {
+  const blink::WebString track_id = MakeTrackId();
+  blink::WebMediaStreamSource webkit_source;

[perkj_chrome, 2015/12/08 09:05:06]

please don't call anything webkit. Maybe just web_source.

[emircan, 2015/12/08 19:28:01]

Done. I was following the naming used in Add*TrackToMediaStream() funcs.

+  scoped_ptr<MediaStreamVideoSource> media_stream_source(
+      new MediaStreamVideoCapturerSource(
+          MediaStreamSource::SourceStoppedCallback(), source.Pass()));
+  webkit_source.initialize(track_id, blink::WebMediaStreamSource::TypeVideo,
+                           track_id, is_remote, is_readonly);
+  webkit_source.setExtraData(media_stream_source.get());
+
+  web_track->initialize(webkit_source);
+  blink::WebMediaConstraints constraints;
+  constraints.initialize();
+  web_track->setExtraData(new MediaStreamVideoTrack(
+      media_stream_source.release(), constraints,
+      MediaStreamVideoSource::ConstraintsCallback(), true));
+  return true;
+}
+
 }  // namespace content