bluetooth: Basic browser tests for chrome://bluetooth-internals.

chrome/browser/resources/bluetooth_internals/interfaces.js

 // Copyright 2016 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.
 
 /**
  * Javascript for Mojo interface helpers, served from
  *     chrome://bluetooth-internals/.
  */
 
 cr.define('interfaces', function() {
@@ skipping 26 matching lines @@
       if (!response.adapter) {
         throw new Error('Bluetooth Not Supported on this platform.');
       }
 
       return interfaces.Connection.bindHandleToProxy(
           response.adapter,
           interfaces.BluetoothAdapter.Adapter);
     });
   }
 
+  /**
+  * Overriden by tests to give them a chance to setup a fake Mojo browser proxy
+  * before any other code executes.
+  * @return {!Promise} A promise firing once necessary setup has been completed.
+  */
+  var setupFn = window.setupFn || function() { return Promise.resolve(); };
+
+  function initialize() {
+    return setupFn().then(initializeProxies);
+  }
+
   return {
-    initialize: initializeProxies,
+    initialize: initialize,
   };
 });