Add MojoVideoDecoder.

media/mojo/services/mojo_audio_decoder.h

 // Copyright 2016 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_MOJO_SERVICES_MOJO_AUDIO_DECODER_H_
 #define MEDIA_MOJO_SERVICES_MOJO_AUDIO_DECODER_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "media/base/audio_decoder.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace media {
 
-// An AudioDecoder that proxies to a interfaces::AudioDecoder.
+// An AudioDecoder that proxies to an interfaces::AudioDecoder.
 class MojoAudioDecoder : public AudioDecoder {
  public:
   MojoAudioDecoder();
   ~MojoAudioDecoder() final;
 
   // AudioDecoder implementation.
   std::string GetDisplayName() const final;
   void Initialize(const AudioDecoderConfig& config,
                   CdmContext* cdm_context,
                   const InitCB& init_cb,
                   const OutputCB& output_cb) final;
   void Decode(const scoped_refptr<DecoderBuffer>& buffer,
               const DecodeCB& decode_cb) final;
   void Reset(const base::Closure& closure) final;
   bool NeedsBitstreamConversion() const final;
 
  private:
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoAudioDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_MOJO_SERVICES_MOJO_AUDIO_DECODER_H_