[Chromecast] Upgrade to new CMA backend API

chromecast/public/media/BUILD.gn

 # 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.
 
 source_set("media") {
   sources = [
-    "audio_pipeline_device.h",
     "cast_decoder_buffer.h",
     "cast_decrypt_config.h",
     "cast_key_system.h",
     "decoder_config.h",
-    "media_clock_device.h",
-    "media_component_device.h",
     "media_pipeline_backend.h",
     "media_pipeline_device_params.h",
     "stream_id.h",
-    "video_pipeline_device.h",
   ]
 
   public_configs = [ ":public_headers" ]
 }
 
 # Any target which includes headers in ":media" should include it in its deps
 # so that it inherits the config below. This allows headers in ":media" to
 # include other interfaces without an absolute path from src.
 config("public_headers") {
   include_dirs = [ "//chromecast/public" ]
 }