Plumb file system permission into WebviewGuest.

chrome/renderer/resources/extensions/web_view.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 module implements Webview (<webview>) as a custom element that wraps a
 // BrowserPlugin object element. The object element is hidden within
 // the shadow DOM of the Webview element.
 
 var DocumentNatives = requireNative('document_natives');
 var EventBindings = require('event_bindings');
@@ skipping 810 matching lines @@
     },
     enumerable: true
   });
 };
 
 /**
  * @private
  */
 WebViewInternal.prototype.getPermissionTypes = function() {
   var permissions =
-      ['media', 'geolocation', 'pointerLock', 'download', 'loadplugin'];
+      ['media',
+      'geolocation',
+      'pointerLock',
+      'download',
+      'loadplugin',
+      'filesystem'];
   return permissions.concat(this.maybeGetExperimentalPermissions());
 };
 
 /**
  * @private
  */
 WebViewInternal.prototype.handleDialogEvent =
     function(event, webViewEvent) {
   var showWarningMessage = function(dialogType) {
     var VOWELS = ['a', 'e', 'i', 'o', 'u'];
@@ skipping 615 matching lines @@
 
 /**
  * Implemented when the experimental API is available.
  * @private
  */
 WebViewInternal.prototype.setupExperimentalContextMenus_ = function() {};
 
 exports.WebView = WebView;
 exports.WebViewInternal = WebViewInternal;
 exports.CreateEvent = CreateEvent;