GuestView constants are now frozen (and thus actually constant).

extensions/renderer/resources/guest_view/web_view/web_view_constants.js

 // Copyright (c) 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 contains constants used in webview.
 
 // Container for the webview constants.
 var WebViewConstants = {
   // Attributes.
   ATTRIBUTE_ALLOWTRANSPARENCY: 'allowtransparency',
@@ skipping 22 matching lines @@
   ERROR_MSG_PERMISSION_ACTION_ALREADY_TAKEN: '<webview>: ' +
       'Permission has already been decided for this "permissionrequest" event.',
   ERROR_MSG_INVALID_PARTITION_ATTRIBUTE: '<webview>: ' +
       'Invalid partition attribute.',
   WARNING_MSG_DIALOG_REQUEST_BLOCKED: '<webview>: %1 %2 dialog was blocked.',
   WARNING_MSG_NEWWINDOW_REQUEST_BLOCKED: '<webview>: A new window was blocked.',
   WARNING_MSG_PERMISSION_REQUEST_BLOCKED: '<webview>: ' +
       'The permission request for "%1" has been denied.'
 };
 
+Object.freeze(WebViewConstants);

[Fady Samuel, 2015/03/20 15:57:27]

nit: $Object

[paulmeyer, 2015/03/20 16:16:15]

Actually, $Object.freeze doesn't exist. I tried that first and then took the '$'
off. I forgot to take it off the one in extension_view_constants.js though. I've
done that too now.

+
 exports.WebViewConstants = WebViewConstants;

[Fady Samuel, 2015/03/20 15:57:27]

You can save a couple of lines of code:

exports.WebViewContants = $Object.freeze(WebViewConstants);

[paulmeyer, 2015/03/20 16:16:15]

Done.