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

extensions/renderer/resources/guest_view/guest_view.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 a wrapper for a guestview that manages its
 // creation, attaching, and destruction.
 
 var EventBindings = require('event_bindings');
 var GuestViewInternal =
     require('binding').Binding.create('guestViewInternal').generate();
@@ skipping 202 matching lines @@
     this.handleCallback(callback);
     return;
   }
 
   if (this.state == GUEST_STATE_START) {
     // destroy() does nothing in this case.
     this.handleCallback(callback);
     return;
   }
 
+  // If this guest is attached, then detach it first.
+  if (!!this.internalInstanceId) {
+    GuestViewInternalNatives.DetachGuest(this.internalInstanceId);
+  }
+
   GuestViewInternal.destroyGuest(this.id,
                                  this.handleCallback.bind(this, callback));
 
   // Reset the state of the destroyed guest;
   this.contentWindow = null;
   this.id = 0;
   this.internalInstanceId = 0;
   this.state = GUEST_STATE_START;
   if (ResizeEvent.hasListener(this.callOnResize)) {
     ResizeEvent.removeListener(this.callOnResize);
@@ skipping 84 matching lines @@
 };
 
 // Returns the ID for this guestview.
 GuestView.prototype.getId = function() {
   var internal = privates(this).internal;
   return internal.id;
 };
 
 // Exports
 exports.GuestView = GuestView;