[Webapp Refactor] Implement AppRemotingActivity.

remoting/webapp/app_remoting/js/ar_main.js

Index: remoting/webapp/app_remoting/js/ar_main.js
diff --git a/remoting/webapp/app_remoting/js/ar_main.js b/remoting/webapp/app_remoting/js/ar_main.js
index 2efe129e03ce323801c0e9814573cfe78edae02f..a1bf4e0583c76d9e5abb4052a2df06c7b88e0bb0 100644
--- a/remoting/webapp/app_remoting/js/ar_main.js
+++ b/remoting/webapp/app_remoting/js/ar_main.js
@@ -11,7 +11,7 @@ var remoting = remoting || {};
  * Entry point ('load' handler) for App Remoting webapp.
  */
 remoting.startAppRemoting = function() {
-  remoting.app = new remoting.AppRemoting(remoting.app_capabilities());
+  remoting.app = new remoting.AppRemoting();

[garykac, 2015/04/15 01:01:23]

Since this is the only "public" entry point, we need the capabilities to be
passed in here. We don't want clients to have to implement
remoting.app_capabilities() - that's a workaround so that we can share a single
ar_main.js file for the various AppRemoting apps.

   remoting.app.start();
 };