Refactor AudioRendererMixer to be more generic.

content/renderer/media/audio_renderer_mixer_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_
 #define CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_
 
 #include <map>
 #include <utility>
 
@@ skipping 32 matching lines @@
       media::AudioHardwareConfig* hardware_config);
   ~AudioRendererMixerManager();
 
   // Creates an AudioRendererMixerInput with the proper callbacks necessary to
   // retrieve an AudioRendererMixer instance from AudioRendererMixerManager.
   // |source_render_view_id| refers to the RenderView containing the entity
   // rendering the audio.  Caller must ensure AudioRendererMixerManager outlives
   // the returned input.
   media::AudioRendererMixerInput* CreateInput(int source_render_view_id);
 
+  // Returns a mixer instance based on AudioParameters; an existing one if one
+  // with the provided AudioParameters exists or a new one if not.
+  media::AudioRendererMixer* GetMixer(int source_render_view_id,
+                                      const media::AudioParameters& params);
+
+  // Remove a mixer instance given a mixer if the only other reference is held
+  // by AudioRendererMixerManager.  Every AudioRendererMixer owner must call
+  // this method when it's done with a mixer.
+  void RemoveMixer(int source_render_view_id,
+                   const media::AudioParameters& params);
+
  private:
   friend class AudioRendererMixerManagerTest;
 
   // Define a key so that only those AudioRendererMixerInputs from the same
   // RenderView and with the same AudioParameters can be mixed together.
   typedef std::pair<int, media::AudioParameters> MixerKey;
 
   // Map of MixerKey to <AudioRendererMixer, Count>.  Count allows
   // AudioRendererMixerManager to keep track explicitly (v.s. RefCounted which
   // is implicit) of the number of outstanding AudioRendererMixers.
   struct AudioRendererMixerReference {
     media::AudioRendererMixer* mixer;
     int ref_count;
   };
   typedef std::map<MixerKey, AudioRendererMixerReference> AudioRendererMixerMap;
 
   // Overrides the AudioRendererSink implementation for unit testing.
   void SetAudioRendererSinkForTesting(media::AudioRendererSink* sink);
 
-  // Returns a mixer instance based on AudioParameters; an existing one if one
-  // with the provided AudioParameters exists or a new one if not.
-  media::AudioRendererMixer* GetMixer(int source_render_view_id,
-                                      const media::AudioParameters& params);
-
-  // Remove a mixer instance given a mixer if the only other reference is held
-  // by AudioRendererMixerManager.  Every AudioRendererMixer owner must call
-  // this method when it's done with a mixer.
-  void RemoveMixer(int source_render_view_id,
-                   const media::AudioParameters& params);
-
   // Active mixers.
   AudioRendererMixerMap mixers_;
   base::Lock mixers_lock_;
 
   // Audio hardware configuration.  Used to construct output AudioParameters for
   // each AudioRendererMixer instance.
   media::AudioHardwareConfig* const hardware_config_;
 
   media::AudioRendererSink* sink_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererMixerManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_