Audio input debug recording refactoring to reduce thread hops and simplify object ownership

media/audio/audio_input_writer.h

Index: media/audio/audio_input_writer.h
diff --git a/media/audio/audio_input_writer.h b/media/audio/audio_input_writer.h
index 42ca0ba42d6e43c10445261355d6e4bc0f00d4f6..8d0b53734e65bf7bb0689beec9a21f64af66d62d 100644
--- a/media/audio/audio_input_writer.h
+++ b/media/audio/audio_input_writer.h
@@ -17,8 +17,20 @@ class AudioInputWriter {
  public:
   virtual ~AudioInputWriter() {}
 
+  // Must be called before calling Write() for the first time after creation or
+  // Stop() call. Can be called on any sequence; Write() and Stop() must be
+  // called on the same sequence as Start().
+  virtual void Start(const base::FilePath& file) = 0;
+
+  // Must be called to finish recording. Each call to Start() requires a call to
+  // Stop(). Will be automatically called on destruction.
+  virtual void Stop() = 0;
+
   // Write |data| to file.
   virtual void Write(std::unique_ptr<AudioBus> data) = 0;
+
+  // Returns true if started. Can be called from any sequence.
+  virtual bool IsRecording() = 0;
 };
 
 }  // namspace media