Make chrome/browser/chromeos/accessibility compile on Athena with use_ash=0

ash/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc

 // Copyright 2014 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/system/chromeos/virtual_keyboard/virtual_keyboard_tray.h"
 
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_constants.h"
 #include "ash/shell.h"
 #include "ash/system/status_area_widget.h"
@@ skipping 85 matching lines @@
   return true;
 }
 
 void VirtualKeyboardTray::ButtonPressed(views::Button* sender,
                                         const ui::Event& event) {
   DCHECK_EQ(button_, sender);
   PerformAction(event);
 }
 
 void VirtualKeyboardTray::OnAccessibilityModeChanged(
-    AccessibilityNotificationVisibility notify) {
+    ui::AccessibilityNotificationVisibility notify) {
   SetVisible(Shell::GetInstance()->accessibility_delegate()->
       IsVirtualKeyboardEnabled());
 }
 
 }  // namespace ash