Load CMA backend from shared library

chromecast/media/base/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.
 
 import("//build/config/crypto.gni")
 import("//chromecast/chromecast.gni")
 
 declare_args() {
   libcast_media_target = ""
 }
 
 source_set("base") {
   sources = [
     "decrypt_context.cc",
     "decrypt_context.h",
     "decrypt_context_clearkey.cc",
     "decrypt_context_clearkey.h",
     "key_systems_common.cc",
     "key_systems_common.h",
     "media_caps.cc",
     "media_caps.h",
+    "media_codec_support.cc",
+    "media_codec_support.h",
     "media_message_loop.cc",
     "media_message_loop.h",
     "switching_media_renderer.cc",
     "switching_media_renderer.h",
   ]
 
   configs += [ "//chromecast:config" ]
 
   deps = [
     "//base",
@@ skipping 21 matching lines @@
   sources = [
     "cast_media_default.cc",
   ]
 
   configs += [ "//chromecast:config" ]
 
   deps = [
     "//chromecast/public",
   ]
 }