[ash-md] Wired in the Shelf color to be derived from the Wallpaper.

ash/common/system/status_area_widget.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/common/system/status_area_widget.h"
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/system/chromeos/ime_menu/ime_menu_tray.h"
 #include "ash/common/system/chromeos/palette/palette_tray.h"
@@ skipping 163 matching lines @@
              ? ui::NativeThemeDarkAura::instance()
              : Widget::GetNativeTheme();
 }
 
 void StatusAreaWidget::OnNativeWidgetActivationChanged(bool active) {
   Widget::OnNativeWidgetActivationChanged(active);
   if (active)
     status_area_widget_delegate_->SetPaneFocusAndFocusDefault();
 }
 
-void StatusAreaWidget::UpdateShelfItemBackground(int alpha) {
-  web_notification_tray_->UpdateShelfItemBackground(alpha);
-  system_tray_->UpdateShelfItemBackground(alpha);
-  virtual_keyboard_tray_->UpdateShelfItemBackground(alpha);
-  logout_button_tray_->UpdateShelfItemBackground(alpha);
-  ime_menu_tray_->UpdateShelfItemBackground(alpha);
+void StatusAreaWidget::UpdateShelfItemBackground(SkColor color) {
+  web_notification_tray_->UpdateShelfItemBackground(color);
+  system_tray_->UpdateShelfItemBackground(color);
+  virtual_keyboard_tray_->UpdateShelfItemBackground(color);
+  logout_button_tray_->UpdateShelfItemBackground(color);
+  ime_menu_tray_->UpdateShelfItemBackground(color);
   if (palette_tray_)
-    palette_tray_->UpdateShelfItemBackground(alpha);
-  overview_button_tray_->UpdateShelfItemBackground(alpha);
+    palette_tray_->UpdateShelfItemBackground(color);
+  overview_button_tray_->UpdateShelfItemBackground(color);
 }
 
 void StatusAreaWidget::AddSystemTray() {
   system_tray_ = new SystemTray(wm_shelf_);
   status_area_widget_delegate_->AddTray(system_tray_);
 }
 
 void StatusAreaWidget::AddWebNotificationTray() {
   DCHECK(system_tray_);
   web_notification_tray_ = new WebNotificationTray(
@@ skipping 28 matching lines @@
   ime_menu_tray_ = new ImeMenuTray(wm_shelf_);
   status_area_widget_delegate_->AddTray(ime_menu_tray_);
 }
 
 void StatusAreaWidget::AddOverviewButtonTray() {
   overview_button_tray_ = new OverviewButtonTray(wm_shelf_);
   status_area_widget_delegate_->AddTray(overview_button_tray_);
 }
 
 }  // namespace ash