Reland of land "media: Refactor MojoMediaClient" with fix.

media/mojo/services/main.cc

Index: media/mojo/services/main.cc
diff --git a/media/mojo/services/main.cc b/media/mojo/services/main.cc
index b3df5c88fd74bc42ea8bb04b5d60959a2fb9f522..2ab7d06a733c53b7e535cb2272f84cf89bfdeea1 100644
--- a/media/mojo/services/main.cc
+++ b/media/mojo/services/main.cc
@@ -14,8 +14,8 @@
   mojo::ApplicationRunner::InitBaseCommandLine();
   mojo::InitLogging();
 
-  scoped_ptr<mojo::ShellClient> app_delegate =
+  scoped_ptr<mojo::ShellClient> shell_client =
       media::MojoMediaApplication::CreateApp();
-  mojo::ApplicationRunner runner(app_delegate.release());
+  mojo::ApplicationRunner runner(shell_client.release());
   return runner.Run(mojo_handle, false /* init_base */);
 }