MediaStream audio: Refactor 3 separate "glue" implementations into one.

content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h

Index: content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h
diff --git a/content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h b/content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h
index 39881c633d6f0bf53df4490454f799a72f35cd95..f0ad79cf2e6625840a050bb1ebcadda58a0a707c 100644
--- a/content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h
+++ b/content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h
@@ -150,7 +150,6 @@ class MockPeerConnectionDependencyFactory
       bool is_screen_capture) override;
   scoped_refptr<webrtc::VideoTrackSourceInterface> CreateVideoSource(
       cricket::VideoCapturer* capturer) override;
-  void CreateWebAudioSource(blink::WebMediaStreamSource* source) override;
   scoped_refptr<webrtc::MediaStreamInterface> CreateLocalMediaStream(
       const std::string& label) override;
   scoped_refptr<webrtc::VideoTrackInterface> CreateLocalVideoTrack(
@@ -168,20 +167,14 @@ class MockPeerConnectionDependencyFactory
       int sdp_mline_index,
       const std::string& sdp) override;
 
-  std::unique_ptr<WebRtcAudioCapturer> CreateAudioCapturer(
-      int render_frame_id,
-      const StreamDeviceInfo& device_info,
-      const blink::WebMediaConstraints& constraints,
-      MediaStreamAudioSource* audio_source) override;
-  void FailToCreateNextAudioCapturer() {
-    fail_to_create_next_audio_capturer_ = true;
-  }
-
   MockAudioSource* last_audio_source() { return last_audio_source_.get(); }
 
+  scoped_refptr<base::SingleThreadTaskRunner> GetWebRtcSignalingThread()
+      const override;
+
  private:
-  bool fail_to_create_next_audio_capturer_;
-  scoped_refptr <MockAudioSource> last_audio_source_;
+  scoped_refptr<MockAudioSource> last_audio_source_;
+  base::Thread signaling_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(MockPeerConnectionDependencyFactory);
 };