Revert of Mojo JS bindings: switch most usage of "connection"/"router" module to "bindings".

extensions/renderer/resources/mime_handler_private_custom_bindings.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * Custom bindings for the mime handler API.
  */
 
 var binding = require('binding').Binding.create('mimeHandlerPrivate');
 
 var NO_STREAM_ERROR =
     'Streams are only available from a mime handler view guest.';
 var STREAM_ABORTED_ERROR = 'Stream has been aborted.';
 
 var servicePromise = Promise.all([
     requireAsync('content/public/renderer/frame_interfaces'),
     requireAsync('extensions/common/api/mime_handler.mojom'),
+    requireAsync('mojo/public/js/router'),
 ]).then(function(modules) {
   var frameInterfaces = modules[0];
   var mojom = modules[1];
-  return new mojom.MimeHandlerServicePtr(
-      frameInterfaces.getInterface(mojom.MimeHandlerService.name));
+  var routerModule = modules[2];
+  return new mojom.MimeHandlerService.proxyClass(new routerModule.Router(
+      frameInterfaces.getInterface(mojom.MimeHandlerService.name)));
 });
 
 // Stores a promise to the GetStreamInfo() result to avoid making additional
 // calls in response to getStreamInfo() calls.
 var streamInfoPromise;
 
 function throwNoStreamError() {
   throw new Error(NO_STREAM_ERROR);
 }
 
@@ skipping 31 matching lines @@
   });
 
   apiFunctions.setHandleRequestWithPromise('abortStream', function() {
     return servicePromise.then(function(service) {
       return service.abortStream().then(function() {});
     }).catch(throwNoStreamError);
   });
 });
 
 exports.$set('binding', binding.generate());