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

extensions/browser/guest_view/extension_options/extension_options_guest.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_GUEST_VIEW_EXTENSION_OPTIONS_EXTENSION_OPTIONS_GUEST_H_
 #define EXTENSIONS_BROWSER_GUEST_VIEW_EXTENSION_OPTIONS_EXTENSION_OPTIONS_GUEST_H_
 
 #include "base/macros.h"
 #include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/guest_view/extension_options/extension_options_guest_delegate.h"
 #include "extensions/browser/guest_view/guest_view.h"
 #include "url/gurl.h"
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 
 class ExtensionOptionsGuest
     : public extensions::GuestView<ExtensionOptionsGuest>,
       public extensions::ExtensionFunctionDispatcher::Delegate {
  public:
   static const char Type[];
   static extensions::GuestViewBase* Create(
       content::WebContents* owner_web_contents,
       int guest_instance_id);
 
   // GuestViewBase implementation.
+  bool CanRunInDetachedState() const override;
   void CreateWebContents(const base::DictionaryValue& create_params,
                          const WebContentsCreatedCallback& callback) override;
-  void DidAttachToEmbedder() override;
   void DidInitialize(const base::DictionaryValue& create_params) override;
   void DidStopLoading() override;
   const char* GetAPINamespace() const override;
   int GetTaskPrefix() const override;
   void GuestSizeChangedDueToAutoSize(const gfx::Size& old_size,
                                      const gfx::Size& new_size) override;
   bool IsAutoSizeSupported() const override;
+  bool IsPreferredSizeModeEnabled() const override;
   void OnPreferredSizeChanged(const gfx::Size& pref_size) override;
-  bool IsPreferredSizeModeEnabled() const override;
 
   // ExtensionFunctionDispatcher::Delegate implementation.
   content::WebContents* GetAssociatedWebContents() const override;
 
   // content::WebContentsDelegate implementation.
   content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) override;
   void CloseContents(content::WebContents* source) override;
   bool HandleContextMenu(const content::ContextMenuParams& params) override;
@@ skipping 17 matching lines @@
   ExtensionOptionsGuest(content::WebContents* owner_web_contents,
                         int guest_instance_id);
   ~ExtensionOptionsGuest() override;
   void OnRequest(const ExtensionHostMsg_Request_Params& params);
 
   scoped_ptr<extensions::ExtensionFunctionDispatcher>
       extension_function_dispatcher_;
   scoped_ptr<extensions::ExtensionOptionsGuestDelegate>
       extension_options_guest_delegate_;
   GURL options_page_;
-  bool has_navigated_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionOptionsGuest);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_GUEST_VIEW_EXTENSION_OPTIONS_EXTENSION_OPTIONS_GUEST_H_