Update references to the extension messaging APIs to point to the "runtime"

chrome/test/data/extensions/api_test/filebrowser_component/remote.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.
 
 // This test file checks if we can read the expected contents
 // (kExpectedContents) from the target file (kFileName). We will try to read
 // the file directly, and using a filesystem handler
 // (chorme/test/data/extensions/api_test/filesystem_handler/). What's
 // interesting is that we'll read the file via a remote mount point.
 // See external_filesystem_apitest.cc for how this is set up.
@@ skipping 98 matching lines @@
       },
       self.errorCallback_.bind(self, 'Error opening file: '));
 };
 
 TestRunner.prototype.runExecuteReadTask = function() {
   chrome.test.assertTrue(!!this.fileEntry_);
 
   // Add listener to be invoked when filesystem handler extension sends us
   // response.
   this.listener_ = this.onHandlerRequest_.bind(this);
-  chrome.extension.onMessageExternal.addListener(this.listener_);
+  chrome.runtime.onMessageExternal.addListener(this.listener_);
 
   var self = this;
   var fileURL = this.fileEntry_.toURL();
   chrome.fileBrowserPrivate.getFileTasks([fileURL], [],
     function(tasks) {
       tasks = self.filterTasks_(tasks);
       if (!tasks || !tasks.length) {
         self.errorCallback_({message: 'No tasks registered'},
                             'Error fetching tasks: ');
         return;
@@ skipping 48 matching lines @@
           },
           self.errorCallback_.bind(self, 'Error creating writer: '));
       },
       self.errorCallback_.bind(self, 'Error opening file: '));
 };
 
 // Processes the response from file handler for which file task was executed.
 TestRunner.prototype.onHandlerRequest_ =
     function(request, sender, sendResponse) {
   // We don't have to listen for a response anymore.
-  chrome.extension.onMessageExternal.removeListener(this.listener_);
+  chrome.runtime.onMessageExternal.removeListener(this.listener_);
 
   this.verifyHandlerRequest(request,
       chrome.test.succeed,
       this.errorCallback_.bind(this, ''));
 };
 
 TestRunner.prototype.verifyHandlerRequest =
     function(request, successCallback, errorCallback) {
   if (!request) {
     errorCallback({message: 'Request from handler not defined.'});
@@ skipping 101 matching lines @@
     testRunner.runCancelTest(kFileName, 'write');
   },
   function cancelTruncate() {
     testRunner.runCancelTest(kFileName, 'truncate');
   },
   function createDir() {
     // Creates new directory.
     testRunner.runGetDirTest(kNewDirectoryPath, true);
   },
 ]);