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

ash/system/tray_caps_lock.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/tray_caps_lock.h"
 
 #include "ash/caps_lock_delegate.h"
 #include "ash/shell.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_views.h"
@@ skipping 84 matching lines @@
     Shell::GetInstance()->caps_lock_delegate()->ToggleCapsLock();
     return true;
   }
 
   views::Label* text_label_;
   views::Label* shortcut_label_;
 
   DISALLOW_COPY_AND_ASSIGN(CapsLockDefaultView);
 };
 
-TrayCapsLock::TrayCapsLock()
-    : TrayImageItem(IDR_AURA_UBER_TRAY_CAPS_LOCK),
+TrayCapsLock::TrayCapsLock(SystemTray* system_tray)
+    : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_CAPS_LOCK),
       default_(NULL),
       detailed_(NULL),
       search_mapped_to_caps_lock_(false),
       caps_lock_enabled_(
           Shell::GetInstance()->caps_lock_delegate()->IsCapsLockEnabled()),
       message_shown_(false) {
 }
 
 TrayCapsLock::~TrayCapsLock() {}
 
@@ skipping 61 matching lines @@
         message_shown_ = true;
       }
     } else if (detailed_) {
       detailed_->GetWidget()->Close();
     }
   }
 }
 
 }  // namespace internal
 }  // namespace ash