Add default impl for DemuxerStream::EnableBitstreamConverter();

media/base/demuxer_stream.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_BASE_DEMUXER_STREAM_H_
 #define MEDIA_BASE_DEMUXER_STREAM_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "media/base/media_export.h"
@@ skipping 51 matching lines @@
   // if type() != AUDIO.
   virtual AudioDecoderConfig audio_decoder_config() = 0;
 
   // Returns the video decoder configuration. It is an error to call this method
   // if type() != VIDEO.
   virtual VideoDecoderConfig video_decoder_config() = 0;
 
   // Returns the type of stream.
   virtual Type type() = 0;
 
-  virtual void EnableBitstreamConverter() = 0;
+  virtual void EnableBitstreamConverter();
 
   // Whether or not this DemuxerStream allows midstream configuration changes.
   //
   // A DemuxerStream that returns 'true' to this may return the 'kConfigChange'
   // status from a Read() call. In this case the client is expected to be
   // capable of taking appropriate action to handle config changes. Otherwise
   // audio_decoder_config() and video_decoder_config()'s return values are
   // guaranteed to remain constant, and the client may make optimizations based
   // on this.
   virtual bool SupportsConfigChanges() = 0;
 
   virtual VideoRotation video_rotation() = 0;
 
  protected:
   // Only allow concrete implementations to get deleted.
   virtual ~DemuxerStream();
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_DEMUXER_STREAM_H_