MediaRecorder: make MediaRecorderHandler a MediaStreamObserver

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..ee5c16628b0669be9ae89047c84000a161a02bc2 100644
--- a/content/public/renderer/media_stream_api.cc
+++ b/content/public/renderer/media_stream_api.cc
@@ -8,6 +8,7 @@
 #include "base/callback.h"
 #include "base/rand_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "content/renderer/media/media_stream.h"
 #include "content/renderer/media/media_stream_audio_source.h"
 #include "content/renderer/media/media_stream_video_capturer_source.h"
 #include "content/renderer/media/media_stream_video_track.h"
@@ -129,4 +130,9 @@ bool AddAudioTrackToMediaStream(
   return true;
 }
 
+CONTENT_EXPORT void AddMediaStreamTowebMediaStream(

[perkj_chrome, 2016/01/07 09:18:00]

? This seems wrong. In production , this happens when the MediaStream is
created. If the MediaStream is created by blink, this is triggered. 

https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/m...

[mcasas, 2016/01/08 00:14:12]

Yes, this is just for content_shell and is only invoked
in blink_test_runner.cc., see my comments elsewhere
as to the need for this method.

+    blink::WebMediaStream* web_stream) {
+  web_stream->setExtraData(new content::MediaStream());
+}
+
 }  // namespace content