Fix WeakPtrFactory member ordering in extensions

extensions/browser/app_window/app_window.h

Index: extensions/browser/app_window/app_window.h
diff --git a/extensions/browser/app_window/app_window.h b/extensions/browser/app_window/app_window.h
index 12029c79744317232f74ea411776b18e9f9f1d61..98f3c8c0b031016d8ff09115c12a0a2173e3e987 100644
--- a/extensions/browser/app_window/app_window.h
+++ b/extensions/browser/app_window/app_window.h
@@ -509,8 +509,6 @@ class AppWindow : public content::NotificationObserver,
   // app window.
   scoped_ptr<web_modal::PopupManager> popup_manager_;
 
-  base::WeakPtrFactory<AppWindow> image_loader_ptr_factory_;
-
   // Bit field of FullscreenType.
   int fullscreen_types_;
 
@@ -548,6 +546,8 @@ class AppWindow : public content::NotificationObserver,
   // Whether |alpha_enabled| was set in the CreateParams.
   bool requested_alpha_enabled_;
 
+  base::WeakPtrFactory<AppWindow> image_loader_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(AppWindow);
 };