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

media/base/renderer.h

 // Copyright 2014 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_RENDERER_H_
 #define MEDIA_BASE_RENDERER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
@@ skipping 11 matching lines @@
  public:
   typedef base::Callback<void(const scoped_refptr<VideoFrame>&)> PaintCB;
   typedef base::Callback<base::TimeDelta()> TimeDeltaCB;
 
   Renderer();
 
   // Stops rendering and fires any pending callbacks.
   virtual ~Renderer();
 
   // Initializes the Renderer with |demuxer_stream_provider|, executing
-  // |init_cb| upon completion.  If initialization failed, fires |error_cb|
-  // before |init_cb|.  |demuxer_stream_provider| must be valid throughout the
-  // lifetime of the Renderer object.  |init_cb| must only be run after this
-  // method has returned.
+  // |init_cb| upon completion.  If initialization fails, only |init_cb| (not
+  // |error_cb|) should be called.  |demuxer_stream_provider| must be valid for
+  // the lifetime of the Renderer object.  |init_cb| must only be run after this
+  // method has returned.  Firing |init_cb| may result in the immediate
+  // destruction of the caller, so it must be run only prior to returning.
   //
   // Permanent callbacks:
   // - |statistics_cb|: Executed periodically with rendering statistics.
   // - |buffering_state_cb|: Executed when buffering state is changed.
   // - |paint_cb|: Executed when there is a VideoFrame ready to paint.  Can be
   //               ignored if the Renderer handles the painting by itself. Can
   //               be called from any thread.
   // - |ended_cb|: Executed when rendering has reached the end of stream.
-  // - |error_cb|: Executed if any error was encountered during rendering.
+  // - |error_cb|: Executed if any error was encountered after initialization.

[xhwang, 2015/01/23 00:22:01]

Can we also update the comments in AudioRenderer and VideoRenderer:

https://code.google.com/p/chromium/codesearch#chromium/src/media/base/audio_r...

https://code.google.com/p/chromium/codesearch#chromium/src/media/base/video_r...

[DaleCurtis, 2015/01/23 20:31:21]

Done.

   virtual void Initialize(DemuxerStreamProvider* demuxer_stream_provider,
-                          const base::Closure& init_cb,
+                          const PipelineStatusCB& init_cb,
                           const StatisticsCB& statistics_cb,
                           const BufferingStateCB& buffering_state_cb,
                           const PaintCB& paint_cb,
                           const base::Closure& ended_cb,
                           const PipelineStatusCB& error_cb) = 0;
 
   // Associates the |cdm_context| with this Renderer for decryption (and
   // decoding) of media data, then fires |cdm_attached_cb| with the result.
   virtual void SetCdm(CdmContext* cdm_context,
                       const CdmAttachedCB& cdm_attached_cb) = 0;
@@ skipping 21 matching lines @@
   // Returns whether |this| renders video.
   virtual bool HasVideo() = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Renderer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_RENDERER_H_