Mojo JS Bindings: Add support for closing Proxy and Stub connections

mojo/public/js/connection.js

Index: mojo/public/js/connection.js
diff --git a/mojo/public/js/connection.js b/mojo/public/js/connection.js
index 90f1f1efae5f334071fc44bad0c63dec691e27e6..223e71128911ea8ddb329a1cbdfea3b5185df07a 100644
--- a/mojo/public/js/connection.js
+++ b/mojo/public/js/connection.js
@@ -168,8 +168,6 @@ define("mojo/public/js/connection", [
     var router = new Router(handle);
     var connection = new BaseConnection(undefined, proxy, router);
     ProxyBindings(proxy).connection = connection;
-    // TODO(hansmuller): Provide a way to explicitly close a proxy.
-    proxy.handleStash = handle;
     return proxy;
   }