Adds new libcast_media shared library for cast_shell media

chromecast/media/base/cast_media_default.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/public/graphics_properties_shlib.h"
+#include "chromecast/public/cast_media_shlib.h"
 
 namespace chromecast {
 
-bool GraphicsPropertiesShlib::IsSupported(
-    Resolution resolution,
-    const std::vector<std::string>& argv) {
-  return true;
+void CastMediaShlib::Initialize(const std::vector<std::string>& argv) {
+}
+
+void CastMediaShlib::Finalize() {
 }
 
 }  // namespace chromecast