media: Support MojoRendererService in the browser process.

media/media_options.gni

Index: media/media_options.gni
diff --git a/media/media_options.gni b/media/media_options.gni
index c2b470930784a99c50d4efe48b7f642365d3c39f..9ac7c5e637990602b4e74dde3fe1708bae859772 100644
--- a/media/media_options.gni
+++ b/media/media_options.gni
@@ -45,10 +45,13 @@ declare_args() {
   # default since it's not available on the normal Web Platform and costs money.
   enable_mpeg2ts_stream_parser = false
 
-  # Enables browser side Content Decryption Modules. Required for android where
-  # the typical PPAPI based CDM is not available.
+  # Enables browser side Content Decryption Modules. Required for embedders
+  # (e.g. Android and ChromeCast) that use a browser side CDM.
   enable_browser_cdms = is_android
 
+  # Experiment to enable mojo based media renderer: http://crbug.com/431776
+  enable_media_mojo_renderer = false
+
   # TODO(GYP): This should be a platform define.
   is_openbsd = false
 }