Debugging for https://crbug.com/601435.

extensions/renderer/resources/keep_alive.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.
 
 define('keep_alive', [
     'content/public/renderer/frame_service_registry',
     'extensions/common/mojo/keep_alive.mojom',
     'mojo/public/js/core',
 ], function(serviceProvider, mojom, core) {
 
+  // Putting the handles somewhere causes them to not get lost.
+  var allHandles = [];
+
   /**
    * An object that keeps the background page alive until closed.
    * @constructor
    * @alias module:keep_alive~KeepAlive
    */
   function KeepAlive() {
     /**
      * The handle to the keep-alive object in the browser.
      * @type {!MojoHandle}
      * @private
      */
     this.handle_ = serviceProvider.connectToService(mojom.KeepAlive.name);
+    allHandles.push(this.handle_);
   }
 
   /**
    * Removes this keep-alive.
    */
   KeepAlive.prototype.close = function() {
     core.close(this.handle_);
   };
 
   var exports = {};
 
   return {
     /**
      * Creates a keep-alive.
      * @return {!module:keep_alive~KeepAlive} A new keep-alive.
      */
     createKeepAlive: function() { return new KeepAlive(); }
   };
 });