Revert of [chromecast] Pass media task runner to MediaPipelineBackendManager.

chromecast/browser/cast_content_browser_client.cc

Index: chromecast/browser/cast_content_browser_client.cc
diff --git a/chromecast/browser/cast_content_browser_client.cc b/chromecast/browser/cast_content_browser_client.cc
index cfb3d856a295b73adbb92fccc9c5124323575755..dc5902ac7e67d80b42745ebef9874ac48bb4bbe7 100644
--- a/chromecast/browser/cast_content_browser_client.cc
+++ b/chromecast/browser/cast_content_browser_client.cc
@@ -109,20 +109,15 @@
 scoped_ptr<media::MediaPipelineBackend>
 CastContentBrowserClient::CreateMediaPipelineBackend(
     const media::MediaPipelineDeviceParams& params) {
-  DCHECK(cast_browser_main_parts_);
-  return media_pipeline_backend_manager()->CreateMediaPipelineBackend(params);
+  return make_scoped_ptr(
+      media::MediaPipelineBackendManager::CreateMediaPipelineBackend(params));
 }
 
 media::MediaResourceTracker*
 CastContentBrowserClient::media_resource_tracker() {
   return cast_browser_main_parts_->media_resource_tracker();
 }
-
-media::MediaPipelineBackendManager*
-CastContentBrowserClient::media_pipeline_backend_manager() {
-  return cast_browser_main_parts_->media_pipeline_backend_manager();
-}
-#endif  // !defined(OS_ANDROID)
+#endif  // OS_ANDROID
 
 void CastContentBrowserClient::SetMetricsClientId(
     const std::string& client_id) {