Added Ash.SystemMenu.DefaultView.VisibleItems histogram.

ash/common/system/audio/tray_audio.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/audio/tray_audio.h"
 
 #include <cmath>
 #include <utility>
 
 #include "ash/common/ash_constants.h"
@@ skipping 24 matching lines @@
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/slider.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/view.h"
 
 namespace ash {
 
 TrayAudio::TrayAudio(SystemTray* system_tray,
                      std::unique_ptr<system::TrayAudioDelegate> audio_delegate)
-    : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_VOLUME_MUTE),
+    : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_VOLUME_MUTE, UMA_AUDIO),
       audio_delegate_(std::move(audio_delegate)),
       volume_view_(NULL),
       pop_up_volume_view_(false) {
   WmShell::Get()->system_tray_notifier()->AddAudioObserver(this);
   display::Screen::GetScreen()->AddObserver(this);
 }
 
 TrayAudio::~TrayAudio() {
   display::Screen::GetScreen()->RemoveObserver(this);
   WmShell::Get()->system_tray_notifier()->RemoveAudioObserver(this);
@@ skipping 121 matching lines @@
   if (tray_view())
     tray_view()->SetVisible(GetInitialVisibility());
   if (volume_view_) {
     volume_view_->SetVolumeLevel(
         static_cast<float>(audio_delegate_->GetOutputVolumeLevel()) / 100.0f);
     volume_view_->Update();
   }
 }
 
 }  // namespace ash