Decouple web_view.js from attribute internals

extensions/renderer/resources/guest_view/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 GuestView = require('guestView').GuestView;
 var GuestViewContainer = require('guestViewContainer').GuestViewContainer;
 var WebViewConstants = require('webViewConstants').WebViewConstants;
 var WebViewEvents = require('webViewEvents').WebViewEvents;
 var WebViewInternal = require('webViewInternal').WebViewInternal;
 
 // Represents the internal state of <webview>.
 function WebViewImpl(webviewElement) {
   GuestViewContainer.call(this, webviewElement, 'webview');
 
-  this.beforeFirstNavigation = true;
-
   this.setupWebViewAttributes();
   this.setupElementProperties();
 
   // on* Event handlers.
   this.on = {};
   new WebViewEvents(this, this.viewInstanceId);
 }
 
 WebViewImpl.prototype.__proto__ = GuestViewContainer.prototype;
 
@@ skipping 32 matching lines @@
 };
 
 // Initiates navigation once the <webview> element is attached to the DOM.
 WebViewImpl.prototype.onElementAttached = function() {
   this.attributes[WebViewConstants.ATTRIBUTE_SRC].parse();
 };
 
 // Resets some state upon detaching <webview> element from the DOM.
 WebViewImpl.prototype.onElementDetached = function() {
   this.guest.destroy();
-  this.beforeFirstNavigation = true;
-  this.attributes[WebViewConstants.ATTRIBUTE_PARTITION].validPartitionId =
-      true;
+  for (var i in this.attributes) {
+    this.attributes[i].reset();
+  }
 };
 
 // Sets the <webview>.request property.
 WebViewImpl.prototype.setRequestPropertyOnWebViewElement = function(request) {
   Object.defineProperty(
       this.element,
       'request',
       {
         value: request,
         enumerable: true
@@ skipping 174 matching lines @@
 WebViewImpl.prototype.setupExperimentalContextMenus = function() {};
 WebViewImpl.prototype.maybeSetupExperimentalChromeWebViewEvents =
   function(request) {
     return request;
 };
 
 GuestViewContainer.registerElement(WebViewImpl);
 
 // Exports.
 exports.WebViewImpl = WebViewImpl;