Added Ash.SystemMenu.DefaultView.VisibleItems histogram.

ash/common/system/chromeos/session/tray_session_length_limit.cc

 // Copyright 2014 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/chromeos/session/tray_session_length_limit.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
@@ skipping 26 matching lines @@
 // with 1000ms).
 const int kTimerIntervalInMilliseconds = 500;
 
 }  // namespace
 
 // static
 const char TraySessionLengthLimit::kNotificationId[] =
     "chrome://session/timeout";
 
 TraySessionLengthLimit::TraySessionLengthLimit(SystemTray* system_tray)
-    : SystemTrayItem(system_tray),
+    : SystemTrayItem(system_tray, UMA_SESSION_LENGTH_LIMIT),
       limit_state_(LIMIT_NONE),
       last_limit_state_(LIMIT_NONE),
       tray_bubble_view_(NULL) {
   WmShell::Get()->system_tray_notifier()->AddSessionLengthLimitObserver(this);
   Update();
 }
 
 TraySessionLengthLimit::~TraySessionLengthLimit() {
   WmShell::Get()->system_tray_notifier()->RemoveSessionLengthLimitObserver(
       this);
@@ skipping 129 matching lines @@
 
 base::string16 TraySessionLengthLimit::ComposeTrayBubbleMessage() const {
   return l10n_util::GetStringFUTF16(
       IDS_ASH_STATUS_TRAY_BUBBLE_SESSION_LENGTH_LIMIT,
       ui::TimeFormat::Detailed(ui::TimeFormat::FORMAT_DURATION,
                                ui::TimeFormat::LENGTH_LONG, 10,
                                remaining_session_time_));
 }
 
 }  // namespace ash