Fix accessability for web notification tray.

ash/wm/shelf_layout_manager.cc

 // 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.
 
 #include "ash/wm/shelf_layout_manager.h"
 
 #include <algorithm>
 
 #include "ash/launcher/launcher.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/status_area_widget.h"
-#include "ash/system/tray/system_tray.h"
-#include "ash/system/web_notification/web_notification_tray.h"
 #include "ash/wm/workspace_controller.h"
 #include "base/auto_reset.h"
 #include "base/i18n/rtl.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/event_filter.h"
 #include "ui/aura/root_window.h"
 #include "ui/base/event.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_observer.h"
 #include "ui/compositor/layer_animator.h"
@@ skipping 484 matching lines @@
   target_bounds->opacity =
       (state.visibility_state == VISIBLE ||
        state.visibility_state == AUTO_HIDE) ? 1.0f : 0.0f;
 }
 
 void ShelfLayoutManager::UpdateShelfBackground(
     BackgroundAnimator::ChangeType type) {
   bool launcher_paints = GetLauncherPaintsBackground();
   if (launcher_)
     launcher_->SetPaintsBackground(launcher_paints, type);
-  // SystemTray normally draws a background, but we don't want it to draw a
+  // The status area normally draws a background, but we don't want it to draw a
   // background when the launcher does.
   StatusAreaWidget* status_area_widget =
       Shell::GetInstance()->status_area_widget();
   if (status_area_widget)
     status_area_widget->SetPaintsBackground(!launcher_paints, type);
 }
 
 bool ShelfLayoutManager::GetLauncherPaintsBackground() const {
   return (!state_.is_screen_locked && window_overlaps_shelf_) ||
       state_.visibility_state == AUTO_HIDE;
@@ skipping 72 matching lines @@
 int ShelfLayoutManager::GetWorkAreaSize(const State& state, int size) const {
   if (state.visibility_state == VISIBLE)
     return size;
   if (state.visibility_state == AUTO_HIDE)
     return kAutoHideSize;
   return 0;
 }
 
 }  // namespace internal
 }  // namespace ash