Added Ash.SystemMenu.DefaultView.VisibleItems histogram.

ash/common/system/tray/system_tray_item.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/tray/system_tray_item.h"
 
 #include "ash/common/system/tray/system_tray.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ui/views/view.h"
 
 namespace ash {
 
-SystemTrayItem::SystemTrayItem(SystemTray* system_tray)
-    : system_tray_(system_tray), restore_focus_(false) {}
+SystemTrayItem::SystemTrayItem(SystemTray* system_tray, UmaType uma_type)
+    : system_tray_(system_tray), uma_type_(uma_type), restore_focus_(false) {}
 
 SystemTrayItem::~SystemTrayItem() {}
 
 views::View* SystemTrayItem::CreateTrayView(LoginStatus status) {
   return NULL;
 }
 
 views::View* SystemTrayItem::CreateDefaultView(LoginStatus status) {
   return NULL;
 }
@@ skipping 46 matching lines @@
 
 bool SystemTrayItem::ShouldHideArrow() const {
   return false;
 }
 
 bool SystemTrayItem::ShouldShowShelf() const {
   return true;
 }
 
 }  // namespace ash