Added Ash.SystemMenu.DefaultView.VisibleItems histogram.

ash/system/chromeos/rotation/tray_rotation_lock.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/system/chromeos/rotation/tray_rotation_lock.h"
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/system/tray/system_tray.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_item_more.h"
@@ skipping 87 matching lines @@
   base::string16 label = l10n_util::GetStringUTF16(
       rotation_locked ? IDS_ASH_STATUS_TRAY_ROTATION_LOCK_LOCKED
                       : IDS_ASH_STATUS_TRAY_ROTATION_LOCK_AUTO);
   SetLabel(label);
   SetAccessibleName(label);
 }
 
 }  // namespace tray
 
 TrayRotationLock::TrayRotationLock(SystemTray* system_tray)
-    : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_AUTO_ROTATION_LOCKED),
+    : TrayImageItem(system_tray,
+                    IDR_AURA_UBER_TRAY_AUTO_ROTATION_LOCKED,
+                    UMA_ROTATION_LOCK),
       observing_rotation_(false),
       observing_shell_(true) {
   WmShell::Get()->AddShellObserver(this);
 }
 
 TrayRotationLock::~TrayRotationLock() {
   StopObservingShell();
 }
 
 void TrayRotationLock::OnRotationLockChanged(bool rotation_locked) {
@@ skipping 56 matching lines @@
 }
 
 void TrayRotationLock::StopObservingShell() {
   if (!observing_shell_)
     return;
   WmShell::Get()->RemoveShellObserver(this);
   observing_shell_ = false;
 }
 
 }  // namespace ash