Splitting media filter's Initialize() into Create() + callback and Seek() + callback.

media/filters/video_renderer_base.h

 // Copyright (c) 2009 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.
 
 // VideoRendererBase creates its own thread for the sole purpose of timing frame
 // presentation.  It handles reading from the decoder and stores the results in
 // a queue of decoded frames, calling OnFrameAvailable() on subclasses to notify
 // when a frame is ready to display.
 //
 // The media filter methods Initialize(), Stop(), SetPlaybackRate() and Seek()
@@ skipping 21 matching lines @@
   virtual ~VideoRendererBase();
 
   // Helper method for subclasses to parse out video-related information from
   // a MediaFormat.  Returns true if |width_out| and |height_out| were assigned.
   static bool ParseMediaFormat(const MediaFormat& media_format,
                                int* width_out, int* height_out);
 
   // MediaFilter implementation.
   virtual void Stop();
   virtual void SetPlaybackRate(float playback_rate);
-  virtual void Seek(base::TimeDelta time);
+  virtual void Seek(base::TimeDelta time, FilterCallback* callback);
 
   // VideoRenderer implementation.
-  virtual bool Initialize(VideoDecoder* decoder);
+  virtual void Initialize(VideoDecoder* decoder, FilterCallback* callback);
 
   // PlatformThread::Delegate implementation.
   virtual void ThreadMain();
 
   // Assigns the current frame, which will never be NULL as long as this filter
   // is initialized.
   void GetCurrentFrame(scoped_refptr<VideoFrame>* frame_out);
 
  protected:
   // Subclass interface.  Called before any other initialization in the base
@@ skipping 43 matching lines @@
   // Used to signal |thread_| as frames are added to |frames_|.  Rule of thumb:
   // always check |state_| to see if it was set to STOPPED after waking up!
   ConditionVariable frame_available_;
 
   // Simple state tracking variable.
   enum State {
     UNINITIALIZED,
     INITIALIZING,
     INITIALIZED,
     STOPPED,
+    ERRORED,
   };
   State state_;
 
   // Video thread handle.
   PlatformThreadHandle thread_;
 
   // Previous time returned from the pipeline.
   base::TimeDelta previous_time_;
 
   float playback_rate_;
 
+  // Filter callbacks.
+  scoped_ptr<FilterCallback> initialize_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoRendererBase);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_VIDEO_RENDERER_BASE_H_