<webview>, <appview> and <extensionoptions> can run in a detached state.

extensions/renderer/resources/guest_view/guest_view_container.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 shared functionality for different guestview
 // containers, such as web_view, app_view, etc.
 
 var DocumentNatives = requireNative('document_natives');
 var GuestView = require('guestView').GuestView;
 var IdGenerator = requireNative('id_generator');
@@ skipping 63 matching lines @@
   this.element.addEventListener('focus', function(e) {
     // Focus the BrowserPlugin when the GuestViewContainer takes focus.
     privates(this).browserPluginElement.focus();
   }.bind(this));
   this.element.addEventListener('blur', function(e) {
     // Blur the BrowserPlugin when the GuestViewContainer loses focus.
     privates(this).browserPluginElement.blur();
   }.bind(this));
 };
 
-GuestViewContainer.prototype.attach = function() {
-  // Augment the attach parameters with the element size, so that the guestview
-  // can fit the element initially.
-  var attachParams = this.buildAttachParams();
-  attachParams['elementWidth'] = parseInt(this.element.offsetWidth);
-  attachParams['elementHeight'] = parseInt(this.element.offsetHeight);
-
-  this.guest.attach(this.internalInstanceId, this.viewInstanceId, attachParams);
-};
-
 GuestViewContainer.prototype.attachWindow = function() {
   if (!this.internalInstanceId) {
     return true;
   }
 
-  this.attach();
+  this.guest.attach(this.internalInstanceId,
+                    this.viewInstanceId,
+                    this.buildParams());
   return true;
 };
 
 GuestViewContainer.prototype.handleBrowserPluginAttributeMutation =
     function(name, oldValue, newValue) {
   if (name == 'internalinstanceid' && !oldValue && !!newValue) {
     privates(this).browserPluginElement.removeAttribute('internalinstanceid');
     this.internalInstanceId = parseInt(newValue);
 
     if (!this.guest.getId()) {
       return;
     }
-    this.attach();
+    this.guest.attach(this.internalInstanceId,
+                      this.viewInstanceId,
+                      this.buildParams());
   }
 };
 
+GuestViewContainer.prototype.buildParams = function() {
+  var params = this.buildContainerParams();
+  params['instanceId'] = this.viewInstanceId;
+  params['elementWidth'] = parseInt(this.element.offsetWidth);
+  params['elementHeight'] = parseInt(this.element.offsetHeight);
+  return params;
+};
+
 // Implemented by the specific view type, if needed.
-GuestViewContainer.prototype.buildAttachParams = function() { return {}; };
+GuestViewContainer.prototype.buildContainerParams = function() { return {}; };
 GuestViewContainer.prototype.handleAttributeMutation = function() {};
 GuestViewContainer.prototype.onElementAttached = function() {};
 GuestViewContainer.prototype.onElementDetached = function() {
   this.guest.destroy();
 };
 
 // Registers the browser plugin <object> custom element. |viewType| is the
 // name of the specific guestview container (e.g. 'webview').
 function registerBrowserPluginElement(viewType) {
   var proto = Object.create(HTMLObjectElement.prototype);
@@ skipping 54 matching lines @@
     }
     internal.handleAttributeMutation(name, oldValue, newValue);
   };
 
   proto.detachedCallback = function() {
     var internal = privates(this).internal;
     if (!internal) {
       return;
     }
     internal.elementAttached = false;
+    internal.internalInstanceId = 0;
     internal.onElementDetached();
   };
 
   // Let the specific view type add extra functionality to its custom element
   // through |proto|.
   if (guestViewContainerType.setupElement) {
     guestViewContainerType.setupElement(proto);
   }
 
   window[guestViewContainerType.VIEW_TYPE] =
       DocumentNatives.RegisterElement(
           guestViewContainerType.VIEW_TYPE.toLowerCase(),
           {prototype: proto});
 
   // Delete the callbacks so developers cannot call them and produce unexpected
   // behavior.
   delete proto.createdCallback;
   delete proto.attachedCallback;
   delete proto.detachedCallback;
   delete proto.attributeChangedCallback;
 }
 
 // Exports.
 exports.GuestViewContainer = GuestViewContainer;