Add the base class for decoder buffers used in cast media.

chromecast/media/cma/base/decoder_buffer_base.cc

 // Copyright 2014 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/common/chromecast_config.h"
+#include "chromecast/media/cma/base/decoder_buffer_base.h"
 
 namespace chromecast {
+namespace media {
 
-void ChromecastConfig::RegisterPlatformPrefs(PrefRegistrySimple* registry) {
+DecoderBufferBase::DecoderBufferBase() {
 }
 
+DecoderBufferBase::~DecoderBufferBase() {
+}
+
+}  // namespace media
 }  // namespace chromecast