[Cast] Refactor/clean-up VideoReceiver to match AudioReceiver as closely as possible.

media/cast/video_receiver/codecs/vp8/vp8_decoder.h

-// Copyright 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.
-
-#ifndef MEDIA_CAST_RTP_RECEVIER_CODECS_VP8_VP8_DECODER_H_
-#define MEDIA_CAST_RTP_RECEVIER_CODECS_VP8_VP8_DECODER_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "base/threading/non_thread_safe.h"
-#include "media/cast/cast_config.h"
-#include "media/cast/cast_environment.h"
-#include "media/cast/cast_receiver.h"
-#include "third_party/libvpx/source/libvpx/vpx/vpx_decoder.h"
-
-typedef struct vpx_codec_ctx vpx_dec_ctx_t;
-
-// TODO(mikhal): Look into reusing VpxVideoDecoder.
-namespace media {
-namespace cast {
-
-// This class is not thread safe; it's only called from the cast video decoder
-// thread.
-class Vp8Decoder : public base::NonThreadSafe {
- public:
-  explicit Vp8Decoder(scoped_refptr<CastEnvironment> cast_environment);
-  ~Vp8Decoder();
-
-  // Decode frame - The decoded frame will be passed via the callback.
-  // Will return false in case of error, and then it's up to the caller to
-  // release the memory.
-  // Ownership of the encoded_frame does not pass to the Vp8Decoder.
-  bool Decode(const transport::EncodedVideoFrame* encoded_frame,
-              const base::TimeTicks render_time,
-              const VideoFrameDecodedCallback& frame_decoded_cb);
-
- private:
-  // Initialize the decoder.
-  void InitDecoder();
-  scoped_ptr<vpx_dec_ctx_t> decoder_;
-  scoped_refptr<CastEnvironment> cast_environment_;
-
-  DISALLOW_COPY_AND_ASSIGN(Vp8Decoder);
-};
-
-}  // namespace cast
-}  // namespace media
-
-#endif  // MEDIA_CAST_RTP_RECEVIER_CODECS_VP8_VP8_DECODER_H_