Make accelerators not to work when the keyboard overlay is shown.

ash/keyboard_overlay/keyboard_overlay_view.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_KEYBOARD_OVERLAY_KEYBOARD_OVERLAY_VIEW_H_
 #define ASH_KEYBOARD_OVERLAY_KEYBOARD_OVERLAY_VIEW_H_
 
 #include "ash/ash_export.h"
+#include "ash/wm/overlay_event_filter.h"
 #include "base/compiler_specific.h"
 #include "ui/views/controls/webview/web_dialog_view.h"
 
 class GURL;
 
 namespace content {
 class BrowserContext;
 }
 
 namespace ui {
 class WebDialogDelegate;
 }
 
 // A customized dialog view for the keyboard overlay.
-class ASH_EXPORT KeyboardOverlayView : public views::WebDialogView {
+class ASH_EXPORT KeyboardOverlayView
+    : public views::WebDialogView,
+      public ash::internal::OverlayEventFilter::Delegate {
  public:
   KeyboardOverlayView(content::BrowserContext* context,
                       ui::WebDialogDelegate* delegate,
                       WebContentsHandler* handler);
   virtual ~KeyboardOverlayView();
 
+  // Overridden from ash::internal::OverlayEventFilter::Delegate:
+  virtual void Cancel() OVERRIDE;
+  virtual bool IsCancelingKeyEvent(aura::KeyEvent* event) OVERRIDE;
+  virtual aura::Window* GetWindow() OVERRIDE;
+
   // Shows the keyboard overlay.
   static void ShowDialog(content::BrowserContext* context,
                          WebContentsHandler* handler,
                          const GURL& url);
 
  private:
   // Overridden from views::WidgetDelegate:
   virtual void WindowClosing() OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(KeyboardOverlayView);
 };
 
 #endif  // ASH_KEYBOARD_OVERLAY_KEYBOARD_OVERLAY_VIEW_H_