[uber] make the navigation controls an iframe

chrome/browser/resources/uber/uber_utils.js

 // Copyright (c) 2012 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.
 
 /**
  * @fileoverview A collection of utility methods for UberPage and its contained
  *     pages.
  */
 
 cr.define('uber', function() {
   /**
    * Invokes a method on the parent window (UberPage). This is a convenience
    * method for API calls into the uber page.
    * @param {String} method The name of the method to invoke.
-   * @param {Object} params Optional property bag of parameters to pass to the
-   *     invoked method.
+   * @param {Object=} opt_params Optional property bag of parameters to pass to
+   *     the invoked method.
    * @private
    */
-  function invokeMethodOnParent(method, params) {
-    if (!window.parent)
+  function invokeMethodOnParent(method, opt_params) {
+    if (window.location == window.parent.location)
       return;
 
-    var data = {method: method, params: params};
-    window.parent.postMessage(data, 'chrome://chrome');
-  };
+    invokeMethodOnWindow(window.parent, method, opt_params, 'chrome://chrome');
+  }
+
+  /**
+   * Invokes a method on the target window.
+   * @param {String} method The name of the method to invoke.
+   * @param {Object=} opt_params Optional property bag of parameters to pass to
+   *     the invoked method.
+   * @param {String=} opt_url The origin of the target window.
+   * @private
+   */
+  function invokeMethodOnWindow(targetWindow, method, opt_params, opt_url) {
+    var data = {method: method, params: opt_params};
+    targetWindow.postMessage(data, opt_url ? opt_url : '*');
+  }
 
   return {
-    invokeMethodOnParent: invokeMethodOnParent
-  }
+    invokeMethodOnParent: invokeMethodOnParent,
+    invokeMethodOnWindow: invokeMethodOnWindow,
+  };
 });