Automated the definitions of webview attributes as properties on the webview node.

extensions/renderer/resources/guest_view/web_view_attributes.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 implements the attributes of the <webview> tag.
 
 var WebView = require('webView').WebView;
 var WebViewConstants = require('webViewConstants').WebViewConstants;
 
 // -----------------------------------------------------------------------------
 // Attribute objects.
 
 // Default implementation of a WebView attribute.
 function WebViewAttribute(name, webViewImpl) {
   this.name = name;
   this.webViewImpl = webViewImpl;
   this.ignoreNextMutation = false;
 }
 
 // Retrieves and returns the attribute's value.
 WebViewAttribute.prototype.getValue = function() {
   return this.webViewImpl.webviewNode.getAttribute(this.name) || '';
 };
 
 // Sets the attribute's value.
 WebViewAttribute.prototype.setValue = function(value) {
   this.webViewImpl.webviewNode.setAttribute(this.name, value || '');
 };
 
+// Defines this attribute as a property on the webview node.
+WebViewAttribute.prototype.define = function() {
+  Object.defineProperty(this.webViewImpl.webviewNode, this.name, {
+    get: function() {
+      return this.getValue();
+    }.bind(this),
+    set: function(value) {
+      this.setValue(value);
+    }.bind(this),
+    enumerable: true
+  });
+};
+
 // Called when the attribute's value changes.
-WebViewAttribute.prototype.handleMutation = function() {}
+WebViewAttribute.prototype.handleMutation = function(oldValue, newValue) {};
 
-// Attribute specifying whether transparency is allowed in the webview.
+// An attribute that is treated as a Boolean.
 function BooleanAttribute(name, webViewImpl) {
   WebViewAttribute.call(this, name, webViewImpl);
 }
 
 BooleanAttribute.prototype = new WebViewAttribute();
 
 BooleanAttribute.prototype.getValue = function() {
-  // This attribute is treated as a boolean, and is retrieved as such.
   return this.webViewImpl.webviewNode.hasAttribute(this.name);
-}
+};
 
 BooleanAttribute.prototype.setValue = function(value) {
   if (!value) {
     this.webViewImpl.webviewNode.removeAttribute(this.name);
   } else {
     this.webViewImpl.webviewNode.setAttribute(this.name, '');
   }
-}
+};
 
 // Attribute representing the state of the storage partition.
 function Partition(webViewImpl) {
   WebViewAttribute.call(this,
                         WebViewConstants.ATTRIBUTE_PARTITION,
                         webViewImpl);
   this.validPartitionId = true;
 }
 
 Partition.prototype = new WebViewAttribute();
 
 Partition.prototype.handleMutation = function(oldValue, newValue) {
   newValue = newValue || '';
 
   // The partition cannot change if the webview has already navigated.
   if (!this.webViewImpl.beforeFirstNavigation) {
     window.console.error(WebViewConstants.ERROR_MSG_ALREADY_NAVIGATED);
     this.ignoreNextMutation = true;
     this.webViewImpl.webviewNode.setAttribute(this.name, oldValue);
     return;
   }
   if (newValue == 'persist:') {
     this.validPartitionId = false;
     window.console.error(
         WebViewConstants.ERROR_MSG_INVALID_PARTITION_ATTRIBUTE);
   }
-}
+};
 
 // -----------------------------------------------------------------------------
 
 // Sets up all of the webview attributes.
 WebView.prototype.setupWebViewAttributes = function() {
   this.attributes = {};
 
   // Initialize the attributes with special behavior (and custom attribute
   // objects).
   this.attributes[WebViewConstants.ATTRIBUTE_ALLOWTRANSPARENCY] =
       new BooleanAttribute(WebViewConstants.ATTRIBUTE_ALLOWTRANSPARENCY, this);
   this.attributes[WebViewConstants.ATTRIBUTE_AUTOSIZE] =
       new BooleanAttribute(WebViewConstants.ATTRIBUTE_AUTOSIZE, this);
   this.attributes[WebViewConstants.ATTRIBUTE_PARTITION] = new Partition(this);
 
   // Initialize the remaining attributes, which have default behavior.
   var defaultAttributes = [WebViewConstants.ATTRIBUTE_MAXHEIGHT,
                            WebViewConstants.ATTRIBUTE_MAXWIDTH,
                            WebViewConstants.ATTRIBUTE_MINHEIGHT,
                            WebViewConstants.ATTRIBUTE_MINWIDTH,
                            WebViewConstants.ATTRIBUTE_NAME,
                            WebViewConstants.ATTRIBUTE_SRC];
   for (var i = 0; defaultAttributes[i]; ++i) {
     this.attributes[defaultAttributes[i]] =
         new WebViewAttribute(defaultAttributes[i], this);
   }
 };