Fix ChunkDemuxer seek deadlock

media/webm/webm_cluster_parser.cc

 // 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.
 
 #include "media/webm/webm_cluster_parser.h"
 
 #include "base/logging.h"
 #include "media/base/data_buffer.h"
+#include "media/ffmpeg/ffmpeg_common.h"
 #include "media/webm/webm_constants.h"
 
 namespace media {
 
 static Buffer* CreateBuffer(const uint8* data, size_t size) {
-  scoped_array<uint8> buf(new uint8[size]);
+  // Why FF_INPUT_BUFFER_PADDING_SIZE? FFmpeg assumes all input buffers are
+  // padded with this value.
+  scoped_array<uint8> buf(new uint8[size + FF_INPUT_BUFFER_PADDING_SIZE]);
   memcpy(buf.get(), data, size);
+  memset(buf.get() + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
   return new DataBuffer(buf.Pass(), size);
 }
 
 WebMClusterParser::WebMClusterParser(int64 timecode_scale,
                                      int audio_track_num,
                                      base::TimeDelta audio_default_duration,
                                      int video_track_num,
                                      base::TimeDelta video_default_duration)
     : timecode_multiplier_(timecode_scale / 1000.0),
       audio_track_num_(audio_track_num),
@@ skipping 96 matching lines @@
     buffer->SetDuration(video_default_duration_);
     queue = &video_buffers_;
   } else {
     DVLOG(1) << "Unexpected track number " << track_num;
     return false;
   }
 
   if (!queue->empty() &&
       buffer->GetTimestamp() == queue->back()->GetTimestamp()) {
     DVLOG(1) << "Got SimpleBlock timecode is not strictly monotonically "
-            << "increasing for track " << track_num;
+             << "increasing for track " << track_num;
     return false;
   }
 
   queue->push_back(buffer);
   return true;
 }
 
 }  // namespace media