remoting: Fix JSCompiler issues blocking ES6 transition.

remoting/webapp/js_proto/chrome_mocks.js

 // Copyright 2014 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.
 
 // This file contains various mock objects for the chrome platform to make
 // unit testing easier.
 
 var chromeMocks = {};
 
 (function(){
@@ skipping 19 matching lines @@
     if (this.listeners_[i] === callback) {
       this.listeners_.splice(i, 1);
       break;
     }
   }
 };
 
 /**
  * @param {...*} var_args
  * @return {void}
+ * @suppress {reportUnknownTypes}
  */
 chromeMocks.Event.prototype.mock$fire = function(var_args) {
   var params = Array.prototype.slice.call(arguments);
   this.listeners_.forEach(
       /** @param {Function} listener */
       function(listener){
         listener.apply(null, params);
       });
 };
 
@@ skipping 241 matching lines @@
     throw new Error('You must call activate() before restore().');
   }
   for (var components in originals_) {
     chrome[components] = originals_[components];
   }
   originals_ = null;
   nativePorts = null;
 };
 
 })();