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

extensions/browser/guest_view/web_view/web_view_guest.h

Index: extensions/browser/guest_view/web_view/web_view_guest.h
diff --git a/extensions/browser/guest_view/web_view/web_view_guest.h b/extensions/browser/guest_view/web_view/web_view_guest.h
index 4a21b2e97d4da882ee5674cbb948acd9ed813931..32ed6c6d0062e73bf01541257379061d4aebb0ec 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest.h
+++ b/extensions/browser/guest_view/web_view/web_view_guest.h
@@ -91,14 +91,15 @@ class WebViewGuest : public GuestView<WebViewGuest>,
                            std::string* error);
 
   // GuestViewBase implementation.
-  const char* GetAPINamespace() const override;
-  int GetTaskPrefix() const override;
+  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;
   void EmbedderWillBeDestroyed() override;
+  const char* GetAPINamespace() const override;
+  int GetTaskPrefix() const override;
   void GuestDestroyed() override;
   void GuestReady() override;
   void GuestSizeChangedDueToAutoSize(const gfx::Size& old_size,
@@ -162,13 +163,13 @@ class WebViewGuest : public GuestView<WebViewGuest>,
                           content::WebContents* new_contents) override;
 
   // BrowserPluginGuestDelegate implementation.
-  bool CanRunInDetachedState() const override;
   content::WebContents* CreateNewGuestWindow(
       const content::WebContents::CreateParams& create_params) override;
   void RequestPointerLockPermission(
       bool user_gesture,
       bool last_unlocked_by_target,
       const base::Callback<void(bool)>& callback) override;
+
   // NotificationObserver implementation.
   void Observe(int type,
                const content::NotificationSource& source,