Add histogram WebRTC.UserMediaRequest.NoResultState to track user media requests with no result.

content/renderer/media/media_stream_impl.h

Index: content/renderer/media/media_stream_impl.h
diff --git a/content/renderer/media/media_stream_impl.h b/content/renderer/media/media_stream_impl.h
index 0effc2a9074863c3dc6764625a4d2839a3332a31..b2e11412d007510cc0bf01988de2a3c93f4fec1e 100644
--- a/content/renderer/media/media_stream_impl.h
+++ b/content/renderer/media/media_stream_impl.h
@@ -147,6 +147,7 @@ class CONTENT_EXPORT MediaStreamImpl
     void RemoveSource(const blink::WebMediaStreamSource& source);
 
     bool AreAllSourcesRemoved() const { return sources_.empty(); }

[vrk (LEFT CHROMIUM), 2014/08/05 19:05:40]

I think both AreAllSourcesRemoved and HasPendingSources should be un-inlined
(http://www.chromium.org/developers/coding-style/cpp-dos-and-donts#TOC-Stop-in...)

[andresp-chromium, 2014/08/06 10:13:56]

Done.

+    bool HasPendingSources() { return !sources_waiting_for_callback_.empty(); }

[vrk (LEFT CHROMIUM), 2014/08/05 19:05:41]

const?

[andresp-chromium, 2014/08/06 10:13:56]

Done.

 
    private:
     void OnTrackStarted(MediaStreamSource* source, bool success);
@@ -191,10 +192,15 @@ class CONTENT_EXPORT MediaStreamImpl
       UserMediaRequestInfo* request,
       content::MediaStreamRequestResult result);
 
+  void OnStreamGeneratedForCancelledRequest(
+      const StreamDeviceInfoArray& audio_array,
+      const StreamDeviceInfoArray& video_array);
+
   UserMediaRequestInfo* FindUserMediaRequestInfo(int request_id);
   UserMediaRequestInfo* FindUserMediaRequestInfo(
       const blink::WebUserMediaRequest& request);
   void DeleteUserMediaRequestInfo(UserMediaRequestInfo* request);
+  void DeleteAllUserMediaRequests();
 
   MediaDevicesRequestInfo* FindMediaDevicesRequestInfo(int request_id);
   MediaDevicesRequestInfo* FindMediaDevicesRequestInfo(