ash: Do not use MessageLoopForUI when not needed.

ash/wm/toplevel_window_event_handler.cc

 // Copyright (c) 2012 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.
 
 #include "ash/wm/toplevel_window_event_handler.h"
 
 #include "ash/shell.h"
 #include "ash/wm/resize_shadow_controller.h"
 #include "ash/wm/window_resizer.h"
 #include "ash/wm/window_state.h"
@@ skipping 403 matching lines @@
   aura::client::CursorClient* cursor_client =
       aura::client::GetCursorClient(root_window);
   if (cursor_client)
     cursor_client->SetCursor(ui::kCursorPointer);
   if (!AttemptToStartDrag(source, drag_location, HTCAPTION, move_source))
     return aura::client::MOVE_CANCELED;
 
   in_move_loop_ = true;
   bool destroyed = false;
   destroyed_ = &destroyed;
-  base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
+  base::MessageLoop* loop = base::MessageLoop::current();
   base::MessageLoop::ScopedNestableTaskAllower allow_nested(loop);
   base::RunLoop run_loop;
   quit_closure_ = run_loop.QuitClosure();
   run_loop.Run();
   if (destroyed)
     return aura::client::MOVE_CANCELED;
   destroyed_ = NULL;
   in_move_loop_ = false;
   return drag_reverted_ ? aura::client::MOVE_CANCELED :
       aura::client::MOVE_SUCCESSFUL;
@@ skipping 193 matching lines @@
     default:
       NOTREACHED();
   }
 }
 
 void ToplevelWindowEventHandler::ResizerWindowDestroyed() {
   CompleteDrag(DRAG_RESIZER_WINDOW_DESTROYED);
 }
 
 }  // namespace ash