Require Renderer::Initialize() to return a status code via callback.

media/base/audio_renderer.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 MEDIA_BASE_AUDIO_RENDERER_H_
 #define MEDIA_BASE_AUDIO_RENDERER_H_
 
 #include "base/callback.h"
 #include "base/time/time.h"
 #include "media/base/buffering_state.h"
 #include "media/base/decryptor.h"
 #include "media/base/media_export.h"
 #include "media/base/pipeline_status.h"
 
 namespace media {
 
 class DemuxerStream;
 class TimeSource;
 
 class MEDIA_EXPORT AudioRenderer {
  public:
   AudioRenderer();
 
   // Stop all operations and fire all pending callbacks.
   virtual ~AudioRenderer();
 
   // Initialize an AudioRenderer with |stream|, executing |init_cb| upon
-  // completion.
+  // completion. If initialization fails, only |init_cb| (not |error_cb|) will
+  // be called.
   //
   // |set_decryptor_ready_cb| is fired when a Decryptor is needed, i.e. when the
   // |stream| is encrypted.
   //
   // |statistics_cb| is executed periodically with audio rendering stats.
   //
   // |buffering_state_cb| is executed when audio rendering has either run out of
   // data or has enough data to continue playback.
   //
   // |ended_cb| is executed when audio rendering has reached the end of stream.
   //
-  // |error_cb| is executed if an error was encountered.
+  // |error_cb| is executed if an error was encountered after initialization.
   virtual void Initialize(DemuxerStream* stream,
                           const PipelineStatusCB& init_cb,
                           const SetDecryptorReadyCB& set_decryptor_ready_cb,
                           const StatisticsCB& statistics_cb,
                           const BufferingStateCB& buffering_state_cb,
                           const base::Closure& ended_cb,
                           const PipelineStatusCB& error_cb) = 0;
 
   // Returns the TimeSource associated with audio rendering.
   virtual TimeSource* GetTimeSource() = 0;
@@ skipping 12 matching lines @@
   // Sets the output volume.
   virtual void SetVolume(float volume) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AudioRenderer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_RENDERER_H_