[Chromecast] Upgrade to new CMA backend API

chromecast/media/cma/base/cast_decoder_buffer_impl.cc

 // Copyright 2015 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 "chromecast/media/cma/base/cast_decoder_buffer_impl.h"
 
 namespace chromecast {
 namespace media {
 
 CastDecoderBufferImpl::CastDecoderBufferImpl(
@@ skipping 23 matching lines @@
 }
 
 bool CastDecoderBufferImpl::end_of_stream() const {
   return buffer_->end_of_stream();
 }
 
 const scoped_refptr<DecoderBufferBase>& CastDecoderBufferImpl::buffer() const {
   return buffer_;
 }
 
+void CastDecoderBufferImpl::set_buffer(
+    const scoped_refptr<DecoderBufferBase>& buffer) {
+  buffer_ = buffer;
+}
+
 }  // namespace media
 }  // namespace chromecast