Stop using shell::GetInstance()->system_tray() in system tray items

ash/system/settings/tray_settings.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/system/settings/tray_settings.h"
 
 #include "ash/shell.h"
 #include "ash/system/power/power_status_view.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/tray_constants.h"
@@ skipping 96 matching lines @@
  private:
   user::LoginStatus login_status_;
   views::Label* label_;
   ash::internal::PowerStatusView* power_status_view_;
 
   DISALLOW_COPY_AND_ASSIGN(SettingsDefaultView);
  };
 
 }  // namespace tray
 
-TraySettings::TraySettings()
-    : default_view_(NULL) {
+TraySettings::TraySettings(SystemTray* system_tray)
+    : SystemTrayItem(system_tray),
+      default_view_(NULL) {
 }
 
 TraySettings::~TraySettings() {}
 
 views::View* TraySettings::CreateTrayView(user::LoginStatus status) {
   return NULL;
 }
 
 views::View* TraySettings::CreateDefaultView(user::LoginStatus status) {
   if ((status == user::LOGGED_IN_NONE || status == user::LOGGED_IN_LOCKED) &&
@@ skipping 25 matching lines @@
 }
 
 // Overridden from PowerStatusObserver.
 void TraySettings::OnPowerStatusChanged(const PowerSupplyStatus& status) {
   if (default_view_)
     default_view_->UpdatePowerStatus(status);
 }
 
 }  // namespace internal
 }  // namespace ash