Immediately reset for vp8 when there's nothing to flush.

media/gpu/android_video_decode_accelerator.cc

 // Copyright (c) 2013 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.
 
 #include "media/gpu/android_video_decode_accelerator.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 1250 matching lines @@
   bitstreams_notified_in_advance_.clear();
 
   // Any error that is waiting to post can be ignored.
   error_sequence_token_++;
 
   DCHECK(strategy_);
   strategy_->ReleaseCodecBuffers(output_picture_buffers_);
 
   // Some VP8 files require complete MediaCodec drain before we can call
   // MediaCodec.flush() or MediaCodec.reset(). http://crbug.com/598963.
-  if (media_codec_ && codec_config_->codec_ == kCodecVP8) {
+  if (media_codec_ && codec_config_->codec_ == kCodecVP8 &&
+      !bitstream_buffers_in_decoder_.empty()) {

[Tima Vaisburd, 2016/06/16 23:01:34]

What if the decoder stalled, i.e. no input for some time but waiting for more
input? Did you consider having some initial state that ResetCodecState() would
come to? Right now it is NO_ERROR which is the same as during normal playback...

[DaleCurtis, 2016/06/16 23:20:47]

Does it matter? I assume if the decoder has nothing in it, we wouldn't hit the
issue this fix is solving.

[Tima Vaisburd, 2016/06/16 23:47:29]

If the decoder has nothing inside, we proceed to ResetCodecState() and flush().
I agree that this flush() should not hang...

     // Postpone ResetCodecState() after the drain.
     StartCodecDrain(DRAIN_FOR_RESET);
   } else {
     ResetCodecState();
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(&AndroidVideoDecodeAccelerator::NotifyResetDone,
                               weak_this_factory_.GetWeakPtr()));
   }
 }
 
@@ skipping 368 matching lines @@
     if (MediaCodecUtil::IsSurfaceViewOutputSupported()) {
       capabilities.flags |= VideoDecodeAccelerator::Capabilities::
           SUPPORTS_EXTERNAL_OUTPUT_SURFACE;
     }
   }
 
   return capabilities;
 }
 
 }  // namespace media