MediaStream audio object graph untangling and clean-ups.

content/renderer/media/media_stream_audio_source.h

Index: content/renderer/media/media_stream_audio_source.h
diff --git a/content/renderer/media/media_stream_audio_source.h b/content/renderer/media/media_stream_audio_source.h
index b2f44d2b44d3e582cdbae3da775cff0b292716b8..04dacbd588a2047b70f158ee67555747e4d41902 100644
--- a/content/renderer/media/media_stream_audio_source.h
+++ b/content/renderer/media/media_stream_audio_source.h
@@ -7,6 +7,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 #include "content/renderer/media/media_stream_source.h"
 #include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
@@ -15,6 +16,10 @@
 
 namespace content {
 
+// TODO(miu): In a soon-upcoming set of refactoring changes, this class will
+// become a base class for managing tracks (part of what WebRtcAudioCapturer
+// does today).  Then, the rest of WebRtcAudioCapturer will be rolled into a
+// subclass.   http://crbug.com/577874
 class CONTENT_EXPORT MediaStreamAudioSource
     : NON_EXPORTED_BASE(public MediaStreamSource) {
  public:
@@ -25,27 +30,29 @@ class CONTENT_EXPORT MediaStreamAudioSource
   MediaStreamAudioSource();
   ~MediaStreamAudioSource() override;
 
+  // Returns the MediaStreamAudioSource instance owned by the given blink
+  // |source| or null.
+  static MediaStreamAudioSource* From(const blink::WebMediaStreamSource& track);
+
   void AddTrack(const blink::WebMediaStreamTrack& track,
                 const blink::WebMediaConstraints& constraints,
                 const ConstraintsCallback& callback);
 
-  void SetLocalAudioSource(webrtc::AudioSourceInterface* source) {
-    local_audio_source_ = source;
-  }
+  WebRtcAudioCapturer* audio_capturer() const { return audio_capturer_.get(); }
 
-  void SetAudioCapturer(const scoped_refptr<WebRtcAudioCapturer>& capturer) {
+  void SetAudioCapturer(scoped_ptr<WebRtcAudioCapturer> capturer) {
     DCHECK(!audio_capturer_.get());
-    audio_capturer_ = capturer;
-  }
-
-  const scoped_refptr<WebRtcAudioCapturer>& GetAudioCapturer() {
-    return audio_capturer_;
+    audio_capturer_ = std::move(capturer);
   }
 
   webrtc::AudioSourceInterface* local_audio_source() {
     return local_audio_source_.get();
   }
 
+  void SetLocalAudioSource(scoped_refptr<webrtc::AudioSourceInterface> source) {
+    local_audio_source_ = source;
+  }
+
  protected:
   void DoStopSource() override;
 
@@ -53,12 +60,12 @@ class CONTENT_EXPORT MediaStreamAudioSource
   const int render_frame_id_;
   PeerConnectionDependencyFactory* const factory_;
 
+  scoped_ptr<WebRtcAudioCapturer> audio_capturer_;
+
   // This member holds an instance of webrtc::LocalAudioSource. This is used
   // as a container for audio options.
   scoped_refptr<webrtc::AudioSourceInterface> local_audio_source_;
 
-  scoped_refptr<WebRtcAudioCapturer> audio_capturer_;
-
   DISALLOW_COPY_AND_ASSIGN(MediaStreamAudioSource);
 };