Fix the comment of overlay_filter_ in Shell.

ash/shell.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_SHELL_H_
 #define ASH_SHELL_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 428 matching lines @@
   scoped_ptr<internal::MagnificationController> magnification_controller_;
   scoped_ptr<aura::FocusManager> focus_manager_;
   scoped_ptr<aura::client::UserActionClient> user_action_client_;
   scoped_ptr<internal::MouseCursorEventFilter> mouse_cursor_filter_;
   scoped_ptr<internal::ScreenPositionController> screen_position_controller_;
 
   // An event filter that rewrites or drops an event.
   scoped_ptr<internal::EventRewriterEventFilter> event_rewriter_filter_;
 
   // An event filter that pre-handles key events while the partial
-  // screenshot UI is active.
+  // screenshot UI or the keyboard overlay is active.
   scoped_ptr<internal::OverlayEventFilter> overlay_filter_;
 
   // An event filter which handles system level gestures
   scoped_ptr<internal::SystemGestureEventFilter> system_gesture_filter_;
 
 #if !defined(OS_MACOSX)
   // An event filter that pre-handles global accelerators.
   scoped_ptr<internal::AcceleratorFilter> accelerator_filter_;
 #endif
 
@@ skipping 26 matching lines @@
 
   // Used by ash/shell.
   content::BrowserContext* browser_context_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_