Improve input handling for WaveAudioHandler.

media/audio/sounds/audio_stream_handler.h

Index: media/audio/sounds/audio_stream_handler.h
diff --git a/media/audio/sounds/audio_stream_handler.h b/media/audio/sounds/audio_stream_handler.h
index f814aaef5993b793052fd54bf80105f8c634d57e..2dd77d68e49518af683ce7a32d01ef12cb8fcbb2 100644
--- a/media/audio/sounds/audio_stream_handler.h
+++ b/media/audio/sounds/audio_stream_handler.h
@@ -53,7 +53,8 @@ class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
   // Stops current playback.
   void Stop();
 
-  const WavAudioHandler& wav_audio_handler() const { return wav_audio_; }
+  // If AudioStreamHandler is not initialized, this will return nullptr.
+  const WavAudioHandler* wav_audio_handler() const { return wav_audio_.get(); }

[tommi (sloooow) - chröme, 2015/11/19 09:44:06]

can you add a DCHECK here for the current thread? (see cc file for usage of
base::NonThreadSafe)

[slan, 2015/11/19 18:57:16]

Does this class needs these? All data members are set in the ctor, and all work
is posted to the AudioManagerThread, which guarantees ordering. 

But to be consistent, I've added such a DCHECK to duration(), the replacement
for this method. There are should not be threading concerns, but this will help
find any nonsense and is consistent with the rest of the methods.

 
  private:
   friend class AudioStreamHandlerTest;
@@ -65,7 +66,7 @@ class MEDIA_EXPORT AudioStreamHandler : public base::NonThreadSafe {
   static void SetAudioSourceForTesting(
       AudioOutputStream::AudioSourceCallback* source);
 
-  WavAudioHandler wav_audio_;
+  scoped_ptr<WavAudioHandler> wav_audio_;
   scoped_ptr<AudioStreamContainer> stream_;
 
   bool initialized_;