Extract the element implementation logic to function mods in <webview>.

extensions/renderer/resources/guest_view/web_view/web_view_action_requests.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 module implements helper objects for the dialog, newwindow, and
 // permissionrequest <webview> events.
 
 var MessagingNatives = requireNative('messaging_natives');
 var WebViewConstants = require('webViewConstants').WebViewConstants;
 var WebViewInternal = require('webViewInternal').WebViewInternal;
@@ skipping 145 matching lines @@
       if (!webview || !webview.tagName || webview.tagName != 'WEBVIEW') {
         throw new Error(ERROR_MSG_WEBVIEW_EXPECTED);
       }
 
       var webViewImpl = privates(webview).internal;
       // Update the partition.
       if (this.event.partition) {
         webViewImpl.onAttach(this.event.partition);
       }
 
-      var attached = webViewImpl.attachWindow(this.event.windowId);
+      var attached = webViewImpl.attachWindow$(this.event.windowId);
       if (!attached) {
         window.console.error(ERROR_MSG_NEWWINDOW_UNABLE_TO_ATTACH);
       }
 
       if (this.guestInstanceId != this.webViewImpl.guest.getId()) {
         // If the opener is already gone, then its guestInstanceId will be
         // stale.
         return;
       }
 
@@ skipping 104 matching lines @@
 var WebViewActionRequests = {
   WebViewActionRequest: WebViewActionRequest,
   Dialog: Dialog,
   NewWindow: NewWindow,
   PermissionRequest: PermissionRequest,
   FullscreenPermissionRequest: FullscreenPermissionRequest
 };
 
 // Exports.
 exports.WebViewActionRequests = WebViewActionRequests;