GuestView: Lazily push attributes to the browser process on attach

extensions/renderer/resources/guest_view/web_view/web_view_attributes.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 the attributes of the <webview> tag.
 
 var GuestViewAttributes = require('guestViewAttributes').GuestViewAttributes;
 var WebViewConstants = require('webViewConstants').WebViewConstants;
 var WebViewImpl = require('webView').WebViewImpl;
 var WebViewInternal = require('webViewInternal').WebViewInternal;
@@ skipping 181 matching lines @@
     // src attribute changes normally initiate a navigation. We suppress
     // the next src attribute handler call to avoid reloading the page
     // on every guest-initiated navigation.
     this.setValueIgnoreMutation(oldValue);
     return;
   }
   this.parse();
 };
 
 SrcAttribute.prototype.attach = function() {
+  GuestViewAttributes.Attribute.prototype.attach.call(this);

[paulmeyer, 2015/03/27 22:40:40]

Why are these calls to the base attach/detach needed?

[Fady Samuel, 2015/03/27 22:56:36]

They're unnecessary. They're remnants from an older approach I tried. Thanks for
catching that!

   this.parse();
 };
 
 SrcAttribute.prototype.detach = function() {
+  GuestViewAttributes.Attribute.prototype.detach.call(this);

[paulmeyer, 2015/03/27 22:40:40]

See above.

[Fady Samuel, 2015/03/27 22:56:36]

Done.

   this.beforeFirstNavigation = true;
 };
 
 // The purpose of this mutation observer is to catch assignment to the src
 // attribute without any changes to its value. This is useful in the case
 // where the webview guest has crashed and navigating to the same address
 // spawns off a new process.
 SrcAttribute.prototype.setupMutationObserver =
     function() {
   this.observer = new MutationObserver(function(mutations) {
@@ skipping 52 matching lines @@
 
   var autosizeAttributes = [WebViewConstants.ATTRIBUTE_MAXHEIGHT,
                             WebViewConstants.ATTRIBUTE_MAXWIDTH,
                             WebViewConstants.ATTRIBUTE_MINHEIGHT,
                             WebViewConstants.ATTRIBUTE_MINWIDTH];
   for (var i = 0; autosizeAttributes[i]; ++i) {
     this.attributes[autosizeAttributes[i]] =
         new AutosizeDimensionAttribute(autosizeAttributes[i], this);
   }
 };