Replace "nested message loop" with "nested run loop" in comments.

ash/wm/toplevel_window_event_handler.h

 // 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.
 
 #ifndef ASH_WM_TOPLEVEL_WINDOW_EVENT_HANDLER_H_
 #define ASH_WM_TOPLEVEL_WINDOW_EVENT_HANDLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/wm/wm_toplevel_window_event_handler.h"
 #include "ash/wm/wm_types.h"
@@ skipping 35 matching lines @@
 
  private:
   // Callback from WmToplevelWindowEventHandler once the drag completes.
   void OnDragCompleted(
       wm::WmToplevelWindowEventHandler::DragResult* result_return_value,
       base::RunLoop* run_loop,
       wm::WmToplevelWindowEventHandler::DragResult result);
 
   wm::WmToplevelWindowEventHandler wm_toplevel_window_event_handler_;
 
-  // Are we running a nested message loop from RunMoveLoop().
+  // Are we running a nested run loop from RunMoveLoop().
   bool in_move_loop_ = false;
 
   base::WeakPtrFactory<ToplevelWindowEventHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ToplevelWindowEventHandler);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_TOPLEVEL_WINDOW_EVENT_HANDLER_H_