Add a buffering controller for Chromecast.

chromecast/chromecast.gyp

Index: chromecast/chromecast.gyp
diff --git a/chromecast/chromecast.gyp b/chromecast/chromecast.gyp
index 5b7ffe40cbd11f4da04d3e2ee538b3df4f76a7bb..6ae9cd214bab5e30cfea220fb50e1580627a0f80 100644
--- a/chromecast/chromecast.gyp
+++ b/chromecast/chromecast.gyp
@@ -161,6 +161,7 @@
         'cast_version_header',
         'chromecast_locales.gyp:chromecast_locales_pak',
         'chromecast_locales.gyp:chromecast_settings',
+        'media/media.gyp:cast_media',
         '../components/components.gyp:component_metrics_proto',
         '../content/content.gyp:content',
         '../content/content.gyp:content_app_browser',
@@ -246,5 +247,12 @@
         },
       ],
     },
+    {
+      'target_name': 'cast_tests',
+      'type': 'none',
+      'dependencies': [
+        'media/media.gyp:cast_media_unittests',
+      ],
+    },
   ],  # end of targets
 }