mash: Migrate remaining tray observers and notify functions.

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/common/keyboard/keyboard_ui.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/shelf_constants.h"
 #include "ash/common/shelf/wm_shelf_util.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_utils.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shell.h"
 #include "ash/system/status_area_widget.h"
-#include "ash/system/tray/system_tray_notifier.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/events/event.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/gfx/vector_icons_public.h"
 #include "ui/views/controls/button/image_button.h"
 
@@ skipping 76 matching lines @@
                                         const ui::Event& event) {
   DCHECK_EQ(button_, sender);
   PerformAction(event);
 }
 
 void VirtualKeyboardTray::OnKeyboardEnabledStateChanged(bool new_value) {
   SetVisible(Shell::GetInstance()->keyboard_ui()->IsEnabled());
 }
 
 }  // namespace ash