Fix VideoRendererBase to allow the decoder to be flushed with a pending read.

media/filters/video_renderer_base.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_FILTERS_VIDEO_RENDERER_BASE_H_
 #define MEDIA_FILTERS_VIDEO_RENDERER_BASE_H_
 
 #include <deque>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 63 matching lines @@
   void PutCurrentFrame(scoped_refptr<VideoFrame> frame);
 
  private:
   // Callback from the video decoder delivering decoded video frames.
   void FrameReady(scoped_refptr<VideoFrame> frame);
 
   // Helper method that schedules an asynchronous read from the decoder as long
   // as there isn't a pending read and we have capacity.
   void AttemptRead_Locked();
 
+  // Called when the VideoDecoder Flush() completes.
+  void OnDecoderFlushDone();
+
   // Attempts to complete flushing and transition into the flushed state.
   void AttemptFlush_Locked();
 
   // Calculates the duration to sleep for based on |current_frame_|'s timestamp,
   // the next frame timestamp (may be NULL), and the provided playback rate.
   //
   // We don't use |playback_rate_| to avoid locking.
   base::TimeDelta CalculateSleepDuration(
       const scoped_refptr<VideoFrame>& next_frame,
       float playback_rate);
@@ skipping 32 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!
   base::ConditionVariable frame_available_;
 
   // State transition Diagram of this class:
   //       [kUninitialized] -------> [kError]
   //              |
   //              | Initialize()
   //              V        All frames returned
-  //   +------[kFlushed]<----------------------[kFlushing]
+  //   +------[kFlushed]<-----[kFlushing]<--- OnDecoderFlushDone()
   //   |          | Seek() or upon                  ^
-  //   |          V got first frame                 |
-  //   |      [kSeeking]                            | Flush()
-  //   |          |                                 |
+  //   |          V got first frame           [kFlushingDecoder]
+  //   |      [kSeeking]                            ^
+  //   |          |                                 | Flush()
   //   |          V Got enough frames               |
   //   |      [kPrerolled]---------------------->[kPaused]
   //   |          |                Pause()          ^
   //   |          V Play()                          |
   //   |       [kPlaying]---------------------------|
   //   |          |                Pause()          ^
   //   |          V Receive EOF frame.              | Pause()
   //   |       [kEnded]-----------------------------+
   //   |                                            ^
   //   |                                            |
   //   +-----> [kStopped]                   [Any state other than]
   //                                        [kUninitialized/kError]
 
   // Simple state tracking variable.
   enum State {
     kUninitialized,
     kPrerolled,
     kPaused,
+    kFlushingDecoder,
     kFlushing,
     kFlushed,
     kSeeking,
     kPlaying,
     kEnded,
     kStopped,
     kError,
   };
   State state_;
 
@@ skipping 31 matching lines @@
   // Callback to execute to inform the player if the video decoder's output is
   // opaque.
   SetOpaqueCB set_opaque_cb_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoRendererBase);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_VIDEO_RENDERER_BASE_H_