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

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 235227189090955df93ef26a83f749be91ed1bc3..3d55f224071dd4d19291dfec3405376a79236b3f 100644
--- a/content/renderer/media/media_stream_audio_source.h
+++ b/content/renderer/media/media_stream_audio_source.h
@@ -6,145 +6,94 @@
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_SOURCE_H_
 
 #include <memory>
-#include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
-#include "content/renderer/media/media_stream_audio_deliverer.h"
 #include "content/renderer/media/media_stream_source.h"
-#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
-#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
+#include "content/renderer/media/webaudio_capturer_source.h"
+#include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
+#include "content/renderer/media/webrtc_audio_capturer.h"
+#include "third_party/webrtc/api/mediastreaminterface.h"
 
 namespace content {
 
 class MediaStreamAudioTrack;
 
-// Represents a source of audio, and manages the delivery of audio data between
-// the source implementation and one or more MediaStreamAudioTracks. This is a
-// base class providing all the necessary functionality to connect tracks and
-// have audio data delivered to them. Subclasses provide the actual audio source
-// implementation (e.g., media::AudioCapturerSource), and should implement the
-// EnsureSourceIsStarted() and EnsureSourceIsStopped() methods, and call
-// SetFormat() and DeliverDataToTracks().
-//
-// This base class can be instantiated, to be used as a place-holder or a "null"
-// source of audio. This can be useful for unit testing, wherever a mock is
-// needed, and/or calls to DeliverDataToTracks() must be made at very specific
-// times.
-//
-// An instance of this class is owned by blink::WebMediaStreamSource.
-//
-// Usage example:
-//
-//   class MyAudioSource : public MediaStreamSource { ... };
-//
-//   blink::WebMediaStreamSource blink_source = ...;
-//   blink::WebMediaStreamTrack blink_track = ...;
-//   blink_source.setExtraData(new MyAudioSource());  // Takes ownership.
-//   if (MediaStreamAudioSource::From(blink_source)
-//           ->ConnectToTrack(blink_track)) {
-//     LOG(INFO) << "Success!";
-//   } else {
-//     LOG(ERROR) << "Failed!";
-//   }
-//   // Regardless of whether ConnectToTrack() succeeds, there will always be a
-//   // MediaStreamAudioTrack instance created.
-//   CHECK(MediaStreamAudioTrack::From(blink_track));
+// 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:
-  explicit MediaStreamAudioSource(bool is_local_source);
+  MediaStreamAudioSource(int render_frame_id,
+                         const StreamDeviceInfo& device_info,
+                         const SourceStoppedCallback& stop_callback,
+                         PeerConnectionDependencyFactory* factory);
+  MediaStreamAudioSource();
   ~MediaStreamAudioSource() override;
 
   // Returns the MediaStreamAudioSource instance owned by the given blink
   // |source| or null.
-  static MediaStreamAudioSource* From(
-      const blink::WebMediaStreamSource& source);
+  static MediaStreamAudioSource* From(const blink::WebMediaStreamSource& track);
 
-  // Provides a weak reference to this MediaStreamAudioSource. The weak pointer
-  // may only be dereferenced on the main thread.
+  void AddTrack(const blink::WebMediaStreamTrack& track,
+                const blink::WebMediaConstraints& constraints,
+                const ConstraintsCallback& callback);
+
   base::WeakPtr<MediaStreamAudioSource> GetWeakPtr() {
     return weak_factory_.GetWeakPtr();
   }
 
-  // Returns true if the source of audio is local to the application (e.g.,
-  // microphone input or loopback audio capture) as opposed to audio being
-  // streamed-in from outside the application.
-  bool is_local_source() const { return is_local_source_; }
+  // Removes |track| from the list of instances that get a copy of the source
+  // audio data.
+  void StopAudioDeliveryTo(MediaStreamAudioTrack* track);
 
-  // Connects this source to the given |track|, creating the appropriate
-  // implementation of the content::MediaStreamAudioTrack interface, which
-  // becomes associated with and owned by |track|. Returns true if the source
-  // was successfully started.
-  bool ConnectToTrack(const blink::WebMediaStreamTrack& track);
+  WebRtcAudioCapturer* audio_capturer() const { return audio_capturer_.get(); }
 
-  // Returns the current format of the audio passing through this source to the
-  // sinks. This can return invalid parameters if the source has not yet been
-  // started. This method is thread-safe.
-  media::AudioParameters GetAudioParameters() const;
+  void SetAudioCapturer(std::unique_ptr<WebRtcAudioCapturer> capturer) {
+    DCHECK(!audio_capturer_.get());
+    audio_capturer_ = std::move(capturer);
+  }
 
-  // Returns a unique class identifier. Some subclasses override and use this
-  // method to provide safe down-casting to their type.
-  virtual void* GetClassIdentifier() const;
+  webrtc::AudioSourceInterface* local_audio_source() {
+    return local_audio_source_.get();
+  }
+
+  void SetLocalAudioSource(scoped_refptr<webrtc::AudioSourceInterface> source) {
+    local_audio_source_ = std::move(source);
+  }
+
+  WebAudioCapturerSource* webaudio_capturer() const {
+    return webaudio_capturer_.get();
+  }
+
+  void SetWebAudioCapturer(std::unique_ptr<WebAudioCapturerSource> capturer) {
+    DCHECK(!webaudio_capturer_.get());
+    webaudio_capturer_ = std::move(capturer);
+  }
 
  protected:
-  // Returns a new MediaStreamAudioTrack. |id| is the blink track's ID in UTF-8.
-  // Subclasses may override this to provide an extended implementation.
-  virtual std::unique_ptr<MediaStreamAudioTrack> CreateMediaStreamAudioTrack(
-      const std::string& id);
-
-  // Returns true if the source has already been started and has not yet been
-  // stopped. Otherwise, attempts to start the source and returns true if
-  // successful. While the source is running, it may provide audio on any thread
-  // by calling DeliverDataToTracks().
-  //
-  // A default no-op implementation is provided in this base class. Subclasses
-  // should override this method.
-  virtual bool EnsureSourceIsStarted();
-
-  // Stops the source and guarantees the the flow of audio data has stopped
-  // (i.e., by the time this method returns, there will be no further calls to
-  // DeliverDataToTracks() on any thread).
-  //
-  // A default no-op implementation is provided in this base class. Subclasses
-  // should override this method.
-  virtual void EnsureSourceIsStopped();
-
-  // Called by subclasses to update the format of the audio passing through this
-  // source to the sinks. This may be called at any time, before or after
-  // tracks have been connected; but must be called at least once before
-  // DeliverDataToTracks(). This method is thread-safe.
-  void SetFormat(const media::AudioParameters& params);
-
-  // Called by subclasses to deliver audio data to the currently-connected
-  // tracks. This method is thread-safe.
-  void DeliverDataToTracks(const media::AudioBus& audio_bus,
-                           base::TimeTicks reference_time);
+  void DoStopSource() override;
 
  private:
-  // MediaStreamSource override.
-  void DoStopSource() final;
+  const int render_frame_id_;
+  PeerConnectionDependencyFactory* const factory_;
 
-  // Removes |track| from the list of instances that get a copy of the source
-  // audio data. The "stop callback" that was provided to the track calls
-  // this.
-  void StopAudioDeliveryTo(MediaStreamAudioTrack* track);
+  // MediaStreamAudioSource is the owner of either a WebRtcAudioCapturer or a
+  // WebAudioCapturerSource.
+  //
+  // TODO(miu): In a series of soon-upcoming changes, WebRtcAudioCapturer and
+  // WebAudioCapturerSource will become subclasses of MediaStreamAudioSource
+  // instead.
+  std::unique_ptr<WebRtcAudioCapturer> audio_capturer_;
+  std::unique_ptr<WebAudioCapturerSource> webaudio_capturer_;
 
-  // True if the source of audio is a local device. False if the source is
-  // remote (e.g., streamed-in from a server).
-  const bool is_local_source_;
-
-  // In debug builds, check that all methods that could cause object graph
-  // or data flow changes are being called on the main thread.
-  base::ThreadChecker thread_checker_;
-
-  // Set to true once this source has been permanently stopped.
-  bool is_stopped_;
-
-  // Manages tracks connected to this source and the audio format and data flow.
-  MediaStreamAudioDeliverer<MediaStreamAudioTrack> deliverer_;
+  // This member holds an instance of webrtc::LocalAudioSource. This is used
+  // as a container for audio options.
+  scoped_refptr<webrtc::AudioSourceInterface> local_audio_source_;
 
   // Provides weak pointers so that MediaStreamAudioTracks won't call
   // StopAudioDeliveryTo() if this instance dies first.