MediaRecorder: make MediaRecorderHandler a MediaStreamObserver

components/test_runner/mock_web_user_media_client.cc

Index: components/test_runner/mock_web_user_media_client.cc
diff --git a/components/test_runner/mock_web_user_media_client.cc b/components/test_runner/mock_web_user_media_client.cc
index 3bd55e5f9f626c5aef65da18da0f0a401e6bb67d..5e695c14e3a85e9f8f1a2daf8cf39319516fde7e 100644
--- a/components/test_runner/mock_web_user_media_client.cc
+++ b/components/test_runner/mock_web_user_media_client.cc
@@ -163,7 +163,7 @@ void MockWebUserMediaClient::requestUserMedia(
     WebMediaStream stream;
     stream.initialize(WebVector<WebMediaStreamTrack>(),
                       WebVector<WebMediaStreamTrack>());
-    stream.setExtraData(new MockExtraData());
+    delegate_->AddMediaStream(&stream);

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

this seems wrong. Why not just do stream.setExtraData(new
content::MediaStream()) if you need this.

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

The gist of this is that test_runner cannot depend on 
content/ [1]. 

(Instead, the idea is to add stuff to a WebTestDelegate  
and implement that accordingly).


[1] https://codereview.chromium.org/1371373002/#msg37

[perkj_chrome, 2016/01/08 07:54:50]

I see. So MockWebUserMediaClient does not actually mock the real implementation
that well.
However, it feels wrong to add a public API in content/public/media_stream that
should never be called by anyone but the layout tests. It should never be called
since content::MediaStream  is created from  MediaStreamCenter if the
mediastream is created from JS.  If the stream has been created in
user_media_client, user_media_client creates content::MediaStream.

 
     if (request.audio() &&
         !delegate_->AddMediaStreamAudioSourceAndTrack(&stream)) {