Redesign the copresence audio handlers.

components/copresence/mediums/audio/audio_recorder.h

Index: components/copresence/mediums/audio/audio_recorder.h
diff --git a/components/copresence/mediums/audio/audio_recorder.h b/components/copresence/mediums/audio/audio_recorder.h
index 5c68eca1808b5c064be2f6426514559186b0adc8..ec7abe5dcd1d8efdd97f9b9a9607fece56d3ea09 100644
--- a/components/copresence/mediums/audio/audio_recorder.h
+++ b/components/copresence/mediums/audio/audio_recorder.h
@@ -25,23 +25,41 @@ class AudioBus;
 namespace copresence {
 
 // The AudioRecorder class will record audio until told to stop.
-class AudioRecorder : public media::AudioInputStream::AudioInputCallback,
-                      public media::AudioConverter::InputCallback {
+class AudioRecorder {
  public:
-  typedef base::Callback<void(const std::string&)> DecodeSamplesCallback;
-
-  explicit AudioRecorder(const DecodeSamplesCallback& decode_callback);
+  typedef base::Callback<void(const std::string&)> RecordedSamplesCallback;
 
   // Initializes the object. Do not use this object before calling this method.
-  virtual void Initialize();
+  virtual void Initialize(const RecordedSamplesCallback& decode_callback) = 0;
 
-  virtual void Record();
-  virtual void Stop();
+  virtual void Record() = 0;
+  virtual void Stop() = 0;
 
   // Cleans up and deletes this object. Do not use object after this call.
-  virtual void Finalize();
+  virtual void Finalize() = 0;
+
+  virtual bool IsRecording() = 0;
+
+ protected:
+  virtual ~AudioRecorder(){};
+};
 
-  bool IsRecording();
+// The AudioRecorder class will record audio until told to stop.
+class AudioRecorderImpl : public AudioRecorder,
+                          public media::AudioInputStream::AudioInputCallback,
+                          public media::AudioConverter::InputCallback {
+ public:
+  typedef base::Callback<void(const std::string&)> RecordedSamplesCallback;
+
+  AudioRecorderImpl();
+
+  // AudioRecorder overrides:
+  virtual void Initialize(
+      const RecordedSamplesCallback& decode_callback) override;
+  virtual void Record() override;
+  virtual void Stop() override;
+  virtual void Finalize() override;
+  virtual bool IsRecording() override;
 
   // Takes ownership of the stream.
   void set_input_stream_for_testing(
@@ -55,7 +73,7 @@ class AudioRecorder : public media::AudioInputStream::AudioInputCallback,
   }
 
  protected:
-  virtual ~AudioRecorder();
+  virtual ~AudioRecorderImpl();
   void set_is_recording(bool is_recording) { is_recording_ = is_recording; }
 
  private:
@@ -92,7 +110,8 @@ class AudioRecorder : public media::AudioInputStream::AudioInputCallback,
   bool is_recording_;
 
   media::AudioInputStream* stream_;
-  DecodeSamplesCallback decode_callback_;
+
+  RecordedSamplesCallback decode_callback_;
 
   // ProvideInput will use this buffer as its source.
   const media::AudioBus* temp_conversion_buffer_;
@@ -108,7 +127,7 @@ class AudioRecorder : public media::AudioInputStream::AudioInputCallback,
   scoped_ptr<media::AudioInputStream> input_stream_for_testing_;
   scoped_ptr<media::AudioParameters> params_for_testing_;
 
-  DISALLOW_COPY_AND_ASSIGN(AudioRecorder);
+  DISALLOW_COPY_AND_ASSIGN(AudioRecorderImpl);
 };
 
 }  // namespace copresence