gdata: Make WeakPtrFactory the last parameter

chrome/browser/chromeos/gdata/gdata_auth_service.h

Index: chrome/browser/chromeos/gdata/gdata_auth_service.h
diff --git a/chrome/browser/chromeos/gdata/gdata_auth_service.h b/chrome/browser/chromeos/gdata/gdata_auth_service.h
index 1acfac25a08fdf4cf56bd320b09579436dd9d796..a79fa236ad80c5d61099b7981696fc346ed98b46 100644
--- a/chrome/browser/chromeos/gdata/gdata_auth_service.h
+++ b/chrome/browser/chromeos/gdata/gdata_auth_service.h
@@ -98,8 +98,10 @@ class GDataAuthService : public content::NotificationObserver {
   ObserverList<Observer> observers_;
 
   content::NotificationRegistrar registrar_;
+
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<GDataAuthService> weak_ptr_factory_;
-  base::WeakPtr<GDataAuthService> weak_ptr_bound_to_ui_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(GDataAuthService);
 };