Record DefaultView.VisibleRows metrics in Unified.

This adds DefaultView.VisibleRows metrics to UnifiedSystemTray. It was
previously implemented in old SystemTray.

PatchSet 1: Moving SystemTrayItem::UmaType to SystemTrayItemUmaType
PatchSet 2: Implement the metrics in UnifiedSystemTray

TEST=manual
BUG=842079

Change-Id: Ied65e288147c59b6df0a8312a86e30a35fa4b953
Reviewed-on: https://chromium-review.googlesource.com/1094821
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567108}

ash/BUILD.gn

@@ -869,6 +869,7 @@ component("ash") {
     "system/tray/system_tray_item.h",
     "system/tray/system_tray_item_detailed_view_delegate.cc",
     "system/tray/system_tray_item_detailed_view_delegate.h",
+    "system/tray/system_tray_item_uma_type.h",
     "system/tray/system_tray_notifier.cc",
     "system/tray/system_tray_notifier.h",
     "system/tray/system_tray_view.cc",

ash/system/audio/tray_audio.cc

@@ -21,7 +21,9 @@ namespace ash {
 using chromeos::CrasAudioHandler;
 
 TrayAudio::TrayAudio(SystemTray* system_tray)
-    : TrayImageItem(system_tray, kSystemTrayVolumeMuteIcon, UMA_AUDIO),
+    : TrayImageItem(system_tray,
+                    kSystemTrayVolumeMuteIcon,
+                    SystemTrayItemUmaType::UMA_AUDIO),
       volume_view_(nullptr),
       pop_up_volume_view_(false),
       audio_detail_view_(nullptr),

ash/system/bluetooth/bluetooth_feature_pod_controller.cc

@@ -43,6 +43,10 @@ void BluetoothFeaturePodController::OnLabelPressed() {
   tray_controller_->ShowBluetoothDetailedView();
 }
 
+SystemTrayItemUmaType BluetoothFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_BLUETOOTH;
+}
+
 void BluetoothFeaturePodController::UpdateButton() {
   bool is_available =
       Shell::Get()->tray_bluetooth_helper()->GetBluetoothAvailable();

ash/system/bluetooth/bluetooth_feature_pod_controller.h

@@ -25,6 +25,7 @@ class BluetoothFeaturePodController : public FeaturePodControllerBase,
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
   void OnLabelPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
  private:
   void UpdateButton();

ash/system/bluetooth/tray_bluetooth.cc

@@ -108,7 +108,7 @@ class BluetoothDefaultView : public TrayItemMore {
 }  // namespace tray
 
 TrayBluetooth::TrayBluetooth(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_BLUETOOTH),
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_BLUETOOTH),
       default_(nullptr),
       detailed_(nullptr),
       detailed_view_delegate_(

ash/system/brightness/tray_brightness.cc

@@ -168,7 +168,8 @@ void BrightnessView::SliderDragEnded(views::Slider* slider) {
 }  // namespace tray
 
 TrayBrightness::TrayBrightness(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_DISPLAY_BRIGHTNESS),
+    : SystemTrayItem(system_tray,
+                     SystemTrayItemUmaType::UMA_DISPLAY_BRIGHTNESS),
       brightness_view_(nullptr),
       current_percent_(100.0),
       got_current_percent_(false),

ash/system/cast/cast_feature_pod_controller.cc

@@ -37,6 +37,10 @@ void CastFeaturePodController::OnIconPressed() {
   tray_controller_->ShowCastDetailedView();
 }
 
+SystemTrayItemUmaType CastFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_CAST;
+}
+
 void CastFeaturePodController::OnDevicesUpdated(
     std::vector<mojom::SinkAndRoutePtr> devices) {
   Update();

ash/system/cast/cast_feature_pod_controller.h

@@ -25,6 +25,7 @@ class ASH_EXPORT CastFeaturePodController
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
   // CastConfigControllerObserver:
   void OnDevicesUpdated(std::vector<mojom::SinkAndRoutePtr> devices) override;

ash/system/cast/tray_cast.cc

@@ -417,7 +417,7 @@ void CastDetailedView::HandleViewClicked(views::View* view) {
 }  // namespace tray
 
 TrayCast::TrayCast(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_CAST),
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_CAST),
       detailed_view_delegate_(
           std::make_unique<SystemTrayItemDetailedViewDelegate>(this)) {
   Shell::Get()->AddShellObserver(this);

ash/system/date/tray_system_info.cc

@@ -17,7 +17,7 @@
 namespace ash {
 
 TraySystemInfo::TraySystemInfo(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_DATE),
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_DATE),
       tray_view_(nullptr),
       default_view_(nullptr) {}
 

ash/system/display_scale/tray_scale.cc

@@ -26,7 +26,7 @@ bool IsDisplayScaleTrayEnabled() {
 }  // namespace
 
 TrayScale::TrayScale(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_NOT_RECORDED),
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_NOT_RECORDED),
       detailed_view_delegate_(
           std::make_unique<SystemTrayItemDetailedViewDelegate>(this)) {}
 

ash/system/enterprise/tray_enterprise.cc

@@ -41,7 +41,8 @@ base::string16 GetEnterpriseMessage() {
 }  // namespace
 
 TrayEnterprise::TrayEnterprise(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_ENTERPRISE), tray_view_(nullptr) {
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_ENTERPRISE),
+      tray_view_(nullptr) {
   Shell::Get()->system_tray_model()->enterprise_domain()->AddObserver(this);
 }
 

ash/system/ime/ime_feature_pod_controller.cc

@@ -57,6 +57,10 @@ void IMEFeaturePodController::OnIconPressed() {
   tray_controller_->ShowIMEDetailedView();
 }
 
+SystemTrayItemUmaType IMEFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_IME;
+}
+
 void IMEFeaturePodController::Update() {
   button_->SetSubLabel(GetLabelString());
   button_->SetVisible(IsButtonVisible());

ash/system/ime/ime_feature_pod_controller.h

@@ -22,6 +22,7 @@ class ASH_EXPORT IMEFeaturePodController : public FeaturePodControllerBase {
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
  private:
   void Update();

ash/system/ime/tray_ime_chromeos.cc

@@ -127,7 +127,7 @@ void IMEDetailedView::ShowSettings() {
 }  // namespace tray
 
 TrayIME::TrayIME(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_IME),
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_IME),
       ime_controller_(Shell::Get()->ime_controller()),
       tray_label_(nullptr),
       default_(nullptr),

ash/system/keyboard_brightness/tray_keyboard_brightness.cc

@@ -102,7 +102,8 @@ void KeyboardBrightnessView::OnBoundsChanged(const gfx::Rect& old_bounds) {
 }  // namespace tray
 
 TrayKeyboardBrightness::TrayKeyboardBrightness(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_DISPLAY_BRIGHTNESS),
+    : SystemTrayItem(system_tray,
+                     SystemTrayItemUmaType::UMA_DISPLAY_BRIGHTNESS),
       weak_ptr_factory_(this) {
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(
       this);

ash/system/media_security/multi_profile_media_tray_item.cc

@@ -55,7 +55,8 @@ class MultiProfileMediaTrayView : public TrayItemView,
 }  // namespace tray
 
 MultiProfileMediaTrayItem::MultiProfileMediaTrayItem(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_MULTI_PROFILE_MEDIA) {}
+    : SystemTrayItem(system_tray,
+                     SystemTrayItemUmaType::UMA_MULTI_PROFILE_MEDIA) {}
 
 MultiProfileMediaTrayItem::~MultiProfileMediaTrayItem() = default;
 

ash/system/message_center/notification_tray_unittest.cc

@@ -75,7 +75,8 @@ SystemTray* GetSystemTray() {
 // Trivial item implementation for testing PopupAndSystemTray test case.
 class TestItem : public SystemTrayItem {
  public:
-  TestItem() : SystemTrayItem(GetSystemTray(), UMA_TEST) {}
+  TestItem()
+      : SystemTrayItem(GetSystemTray(), SystemTrayItemUmaType::UMA_TEST) {}
 
   views::View* CreateDefaultView(LoginStatus status) override {
     views::View* default_view = new views::View;

ash/system/network/network_feature_pod_controller.cc

@@ -49,4 +49,8 @@ void NetworkFeaturePodController::OnLabelPressed() {
   tray_controller_->ShowNetworkDetailedView();
 }
 
+SystemTrayItemUmaType NetworkFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_NETWORK;
+}
+
 }  // namespace ash

ash/system/network/network_feature_pod_controller.h

@@ -23,6 +23,7 @@ class NetworkFeaturePodController : public FeaturePodControllerBase {
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
   void OnLabelPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
  private:
   // Unowned.

ash/system/network/tray_network.cc

@@ -101,7 +101,7 @@ class NetworkDefaultView : public TrayItemMore,
 }  // namespace tray
 
 TrayNetwork::TrayNetwork(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_NETWORK),
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_NETWORK),
       tray_(nullptr),
       default_(nullptr),
       detailed_(nullptr),

ash/system/network/tray_vpn.cc

@@ -142,7 +142,7 @@ class VpnDefaultView : public TrayItemMore,
 }  // namespace tray
 
 TrayVPN::TrayVPN(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_VPN),
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_VPN),
       default_(nullptr),
       detailed_(nullptr),
       detailed_view_delegate_(

ash/system/network/vpn_feature_pod_controller.cc

@@ -45,6 +45,10 @@ void VPNFeaturePodController::OnIconPressed() {
   tray_controller_->ShowVPNDetailedView();
 }
 
+SystemTrayItemUmaType VPNFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_VPN;
+}
+
 void VPNFeaturePodController::Update() {
   // NetworkHandler can be uninitialized in unit tests.
   if (!chromeos::NetworkHandler::IsInitialized())

ash/system/network/vpn_feature_pod_controller.h

@@ -22,6 +22,7 @@ class VPNFeaturePodController : public FeaturePodControllerBase {
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
  private:
   void Update();

ash/system/night_light/night_light_feature_pod_controller.cc

@@ -34,6 +34,10 @@ void NightLightFeaturePodController::OnIconPressed() {
   UpdateButton();
 }
 
+SystemTrayItemUmaType NightLightFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_NIGHT_LIGHT;
+}
+
 void NightLightFeaturePodController::UpdateButton() {
   if (!features::IsNightLightEnabled())
     return;

ash/system/night_light/night_light_feature_pod_controller.h

@@ -19,6 +19,7 @@ class NightLightFeaturePodController : public FeaturePodControllerBase {
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
  private:
   void UpdateButton();

ash/system/night_light/tray_night_light.cc

@@ -11,7 +11,9 @@
 namespace ash {
 
 TrayNightLight::TrayNightLight(SystemTray* system_tray)
-    : TrayImageItem(system_tray, kSystemTrayNightLightIcon, UMA_NIGHT_LIGHT) {
+    : TrayImageItem(system_tray,
+                    kSystemTrayNightLightIcon,
+                    SystemTrayItemUmaType::UMA_NIGHT_LIGHT) {
   Shell::Get()->night_light_controller()->AddObserver(this);
 }
 

ash/system/power/tray_power.cc

@@ -79,8 +79,7 @@ void PowerTrayView::UpdateImage() {
 }  // namespace tray
 
 TrayPower::TrayPower(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_POWER) {
-}
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_POWER) {}
 
 TrayPower::~TrayPower() = default;
 

ash/system/rotation/rotation_lock_feature_pod_controller.cc

@@ -39,6 +39,10 @@ void RotationLockFeaturePodController::OnIconPressed() {
   Shell::Get()->screen_orientation_controller()->ToggleUserRotationLock();
 }
 
+SystemTrayItemUmaType RotationLockFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_ROTATION_LOCK;
+}
+
 void RotationLockFeaturePodController::OnTabletModeStarted() {
   UpdateButton();
 }

ash/system/rotation/rotation_lock_feature_pod_controller.h

@@ -25,6 +25,7 @@ class ASH_EXPORT RotationLockFeaturePodController
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
   // TabletModeObserver:
   void OnTabletModeStarted() override;

ash/system/rotation/tray_rotation_lock.cc

@@ -173,7 +173,7 @@ void RotationLockDefaultView::OnUserRotationLockChanged() {
 TrayRotationLock::TrayRotationLock(SystemTray* system_tray)
     : TrayImageItem(system_tray,
                     kSystemTrayRotationLockLockedIcon,
-                    UMA_ROTATION_LOCK) {
+                    SystemTrayItemUmaType::UMA_ROTATION_LOCK) {
   Shell::Get()->tablet_mode_controller()->AddObserver(this);
 }
 

ash/system/screen_security/screen_capture_tray_item.cc

@@ -19,7 +19,7 @@
 namespace ash {
 
 ScreenCaptureTrayItem::ScreenCaptureTrayItem(SystemTray* system_tray)
-    : ScreenTrayItem(system_tray, UMA_SCREEN_CAPTURE) {
+    : ScreenTrayItem(system_tray, SystemTrayItemUmaType::UMA_SCREEN_CAPTURE) {
   Shell::Get()->AddShellObserver(this);
   Shell::Get()->system_tray_notifier()->AddScreenCaptureObserver(this);
 }

ash/system/screen_security/screen_share_tray_item.cc

@@ -15,7 +15,7 @@
 namespace ash {
 
 ScreenShareTrayItem::ScreenShareTrayItem(SystemTray* system_tray)
-    : ScreenTrayItem(system_tray, UMA_SCREEN_SHARE) {
+    : ScreenTrayItem(system_tray, SystemTrayItemUmaType::UMA_SCREEN_SHARE) {
   Shell::Get()->system_tray_notifier()->AddScreenShareObserver(this);
 }
 

ash/system/screen_security/screen_tray_item.cc

@@ -91,7 +91,8 @@ void ScreenStatusView::UpdateFromScreenTrayItem() {
 
 }  // namespace tray
 
-ScreenTrayItem::ScreenTrayItem(SystemTray* system_tray, UmaType uma_type)
+ScreenTrayItem::ScreenTrayItem(SystemTray* system_tray,
+                               SystemTrayItemUmaType uma_type)
     : SystemTrayItem(system_tray, uma_type),
       tray_view_(nullptr),
       default_view_(nullptr),

ash/system/screen_security/screen_tray_item.h

@@ -73,7 +73,7 @@ class ScreenStatusView : public views::View, public views::ButtonListener {
 // can stop the screen capture/sharing by pressing the stop button.
 class ASH_EXPORT ScreenTrayItem : public SystemTrayItem {
  public:
-  ScreenTrayItem(SystemTray* system_tray, UmaType uma_type);
+  ScreenTrayItem(SystemTray* system_tray, SystemTrayItemUmaType uma_type);
   ~ScreenTrayItem() override;
 
   tray::ScreenTrayView* tray_view() { return tray_view_; }

ash/system/session/tray_session_length_limit.cc

@@ -27,7 +27,8 @@
 namespace ash {
 
 TraySessionLengthLimit::TraySessionLengthLimit(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_SESSION_LENGTH_LIMIT),
+    : SystemTrayItem(system_tray,
+                     SystemTrayItemUmaType::UMA_SESSION_LENGTH_LIMIT),
       model_(Shell::Get()->system_tray_model()->session_length_limit()) {
   model_->AddObserver(this);
   OnSessionLengthLimitUpdated();

ash/system/supervised/tray_supervised_user.cc

@@ -18,7 +18,7 @@
 namespace ash {
 
 TraySupervisedUser::TraySupervisedUser(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_SUPERVISED_USER) {}
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_SUPERVISED_USER) {}
 
 TraySupervisedUser::~TraySupervisedUser() = default;
 

ash/system/tiles/tray_tiles.cc

@@ -10,7 +10,8 @@
 namespace ash {
 
 TrayTiles::TrayTiles(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_NOT_RECORDED), default_view_(nullptr) {}
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_NOT_RECORDED),
+      default_view_(nullptr) {}
 
 TrayTiles::~TrayTiles() = default;
 

ash/system/tray/system_tray.cc

@@ -94,7 +94,8 @@ namespace {
 // A tray item that just reserves space in the tray.
 class PaddingTrayItem : public SystemTrayItem {
  public:
-  PaddingTrayItem() : SystemTrayItem(nullptr, UMA_NOT_RECORDED) {}
+  PaddingTrayItem()
+      : SystemTrayItem(nullptr, SystemTrayItemUmaType::UMA_NOT_RECORDED) {}
   ~PaddingTrayItem() override = default;
 
   // SystemTrayItem:

ash/system/tray/system_tray_bubble.h

@@ -67,7 +67,7 @@ class SystemTrayBubble {
   views::TrayBubbleView* bubble_view_ = nullptr;
 
   // Tracks the views created in the last call to CreateItemViews().
-  std::map<SystemTrayItem::UmaType, views::View*> tray_item_view_map_;
+  std::map<SystemTrayItemUmaType, views::View*> tray_item_view_map_;
 
   int autoclose_delay_;
   base::OneShotTimer autoclose_;

ash/system/tray/system_tray_item.cc

@@ -14,7 +14,8 @@
 
 namespace ash {
 
-SystemTrayItem::SystemTrayItem(SystemTray* system_tray, UmaType uma_type)
+SystemTrayItem::SystemTrayItem(SystemTray* system_tray,
+                               SystemTrayItemUmaType uma_type)
     : system_tray_(system_tray), uma_type_(uma_type), restore_focus_(false) {}
 
 SystemTrayItem::~SystemTrayItem() = default;

ash/system/tray/system_tray_item.h

@@ -10,6 +10,7 @@
 #include "ash/ash_export.h"
 #include "ash/login_status.h"
 #include "ash/public/cpp/shelf_types.h"
+#include "ash/system/tray/system_tray_item_uma_type.h"
 #include "base/macros.h"
 #include "base/timer/timer.h"
 
@@ -28,44 +29,7 @@ class TrayItemView;
 // Detailed view - The submenu shown when the top-level menu row is clicked.
 class ASH_EXPORT SystemTrayItem {
  public:
-  // The different types of SystemTrayItems.
-  //
-  // NOTE: These values are used for UMA metrics so do NOT re-order this enum
-  // and only insert items before the COUNT item.
-  enum UmaType {
-    // SystemTrayItem's with this type are not recorded in the histogram.
-    UMA_NOT_RECORDED = 0,
-    // Used for testing purposes only.
-    UMA_TEST = 1,
-    UMA_ACCESSIBILITY = 2,
-    UMA_AUDIO = 3,
-    UMA_BLUETOOTH = 4,
-    UMA_CAPS_LOCK = 5,
-    UMA_CAST = 6,
-    UMA_DATE = 7,
-    UMA_DISPLAY = 8,
-    UMA_DISPLAY_BRIGHTNESS = 9,
-    UMA_ENTERPRISE = 10,
-    UMA_IME = 11,
-    UMA_MULTI_PROFILE_MEDIA = 12,
-    UMA_NETWORK = 13,
-    UMA_SETTINGS = 14,
-    UMA_UPDATE = 15,
-    UMA_POWER = 16,
-    UMA_ROTATION_LOCK = 17,
-    UMA_SCREEN_CAPTURE = 18,
-    UMA_SCREEN_SHARE = 19,
-    UMA_SESSION_LENGTH_LIMIT = 20,
-    UMA_SMS = 21,
-    UMA_SUPERVISED_USER = 22,
-    UMA_TRACING = 23,
-    UMA_USER = 24,
-    UMA_VPN = 25,
-    UMA_NIGHT_LIGHT = 26,
-    UMA_COUNT = 27,
-  };
-
-  SystemTrayItem(SystemTray* system_tray, UmaType type);
+  SystemTrayItem(SystemTray* system_tray, SystemTrayItemUmaType type);
   virtual ~SystemTrayItem();
 
   // Create* functions may return NULL if nothing should be displayed for the
@@ -150,10 +114,10 @@ class ASH_EXPORT SystemTrayItem {
   // Accesses uma_type().
   friend class SystemTrayView;
 
-  UmaType uma_type() const { return uma_type_; }
+  SystemTrayItemUmaType uma_type() const { return uma_type_; }
 
   SystemTray* system_tray_;
-  UmaType uma_type_;
+  SystemTrayItemUmaType uma_type_;
   bool restore_focus_;
 
   // Used to delay the transition to the detailed view.

ash/system/tray/system_tray_item_uma_type.h

+// Copyright 2018 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.
+
+#ifndef ASH_SYSTEM_TRAY_SYSTEM_TRAY_ITEM_UMA_TYPE_H_
+#define ASH_SYSTEM_TRAY_SYSTEM_TRAY_ITEM_UMA_TYPE_H_
+
+namespace ash {
+
+// The different types of SystemTrayItems.
+//
+// NOTE: These values are used for UMA metrics so do NOT re-order this enum
+// and only insert items before the COUNT item.
+enum class SystemTrayItemUmaType {
+  // SystemTrayItem's with this type are not recorded in the histogram.
+  UMA_NOT_RECORDED = 0,
+  // Used for testing purposes only.
+  UMA_TEST = 1,
+  UMA_ACCESSIBILITY = 2,
+  UMA_AUDIO = 3,
+  UMA_BLUETOOTH = 4,
+  UMA_CAPS_LOCK = 5,
+  UMA_CAST = 6,
+  UMA_DATE = 7,
+  UMA_DISPLAY = 8,
+  UMA_DISPLAY_BRIGHTNESS = 9,
+  UMA_ENTERPRISE = 10,
+  UMA_IME = 11,
+  UMA_MULTI_PROFILE_MEDIA = 12,
+  UMA_NETWORK = 13,
+  UMA_SETTINGS = 14,
+  UMA_UPDATE = 15,
+  UMA_POWER = 16,
+  UMA_ROTATION_LOCK = 17,
+  UMA_SCREEN_CAPTURE = 18,
+  UMA_SCREEN_SHARE = 19,
+  UMA_SESSION_LENGTH_LIMIT = 20,
+  UMA_SMS = 21,
+  UMA_SUPERVISED_USER = 22,
+  UMA_TRACING = 23,
+  UMA_USER = 24,
+  UMA_VPN = 25,
+  UMA_NIGHT_LIGHT = 26,
+  UMA_COUNT = 27,
+};
+
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_TRAY_SYSTEM_TRAY_ITEM_UMA_TYPE_H_

ash/system/tray/system_tray_unittest.cc

@@ -467,7 +467,7 @@ TEST_F(SystemTrayTest, OnlyVisibleItemsRecorded) {
   tray->ShowDefaultView(BUBBLE_CREATE_NEW, false /* show_by_click */);
   RunAllPendingInMessageLoop();
   histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_TEST, 1);
+                                     SystemTrayItemUmaType::UMA_TEST, 1);
 
   ASSERT_TRUE(tray->HasSystemBubble());
   tray->CloseBubble();
@@ -476,7 +476,7 @@ TEST_F(SystemTrayTest, OnlyVisibleItemsRecorded) {
   tray->ShowDefaultView(BUBBLE_CREATE_NEW, false /* show_by_click */);
   RunAllPendingInMessageLoop();
   histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_TEST, 2);
+                                     SystemTrayItemUmaType::UMA_TEST, 2);
 
   ASSERT_TRUE(tray->HasSystemBubble());
   tray->CloseBubble();
@@ -487,7 +487,7 @@ TEST_F(SystemTrayTest, OnlyVisibleItemsRecorded) {
   tray->ShowDefaultView(BUBBLE_CREATE_NEW, false /* show_by_click */);
   RunAllPendingInMessageLoop();
   histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_TEST, 2);
+                                     SystemTrayItemUmaType::UMA_TEST, 2);
 
   ASSERT_TRUE(tray->HasSystemBubble());
   tray->CloseBubble();
@@ -505,15 +505,15 @@ TEST_F(SystemTrayTest, NotRecordedtemsAreNotRecorded) {
   SystemTray* tray = GetPrimarySystemTray();
   ASSERT_TRUE(tray->GetWidget());
 
-  tray->AddTrayItem(
-      std::make_unique<TestSystemTrayItem>(SystemTrayItem::UMA_NOT_RECORDED));
+  tray->AddTrayItem(std::make_unique<TestSystemTrayItem>(
+      SystemTrayItemUmaType::UMA_NOT_RECORDED));
 
   base::HistogramTester histogram_tester;
 
   tray->ShowDefaultView(BUBBLE_CREATE_NEW, false /* show_by_click */);
   RunAllPendingInMessageLoop();
-  histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_NOT_RECORDED, 0);
+  histogram_tester.ExpectBucketCount(
+      kVisibleRowsHistogramName, SystemTrayItemUmaType::UMA_NOT_RECORDED, 0);
 
   ASSERT_TRUE(tray->HasSystemBubble());
   tray->CloseBubble();
@@ -540,7 +540,7 @@ TEST_F(SystemTrayTest, NullDefaultViewIsNotRecorded) {
   tray->ShowDefaultView(BUBBLE_CREATE_NEW, false /* show_by_click */);
   RunAllPendingInMessageLoop();
   histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_TEST, 0);
+                                     SystemTrayItemUmaType::UMA_TEST, 0);
 
   ASSERT_TRUE(tray->HasSystemBubble());
   tray->CloseBubble();
@@ -592,17 +592,17 @@ TEST_F(SystemTrayTest, VisibleDefaultViewIsNotRecordedOnReshow) {
   tray->ShowDefaultView(BUBBLE_CREATE_NEW, false /* show_by_click */);
   RunAllPendingInMessageLoop();
   histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_TEST, 1);
+                                     SystemTrayItemUmaType::UMA_TEST, 1);
 
   tray->ShowDetailedView(test_item, 0, BUBBLE_USE_EXISTING);
   RunAllPendingInMessageLoop();
   histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_TEST, 1);
+                                     SystemTrayItemUmaType::UMA_TEST, 1);
 
   tray->ShowDefaultView(BUBBLE_USE_EXISTING, false /* show_by_click */);
   RunAllPendingInMessageLoop();
   histogram_tester.ExpectBucketCount(kVisibleRowsHistogramName,
-                                     SystemTrayItem::UMA_TEST, 1);
+                                     SystemTrayItemUmaType::UMA_TEST, 1);
 
   ASSERT_TRUE(tray->HasSystemBubble());
   tray->CloseBubble();

ash/system/tray/system_tray_view.cc

@@ -121,12 +121,12 @@ void SystemTrayView::RecordVisibleRowMetrics() {
   if (system_tray_type_ != SYSTEM_TRAY_TYPE_DEFAULT)
     return;
 
-  for (const std::pair<SystemTrayItem::UmaType, views::View*>& pair :
+  for (const std::pair<SystemTrayItemUmaType, views::View*>& pair :
        tray_item_view_map_) {
     if (pair.second->visible() &&
-        pair.first != SystemTrayItem::UMA_NOT_RECORDED) {
+        pair.first != SystemTrayItemUmaType::UMA_NOT_RECORDED) {
       UMA_HISTOGRAM_ENUMERATION("Ash.SystemMenu.DefaultView.VisibleRows",
-                                pair.first, SystemTrayItem::UMA_COUNT);
+                                pair.first, SystemTrayItemUmaType::UMA_COUNT);
     }
   }
 }

ash/system/tray/system_tray_view.h

@@ -40,7 +40,7 @@ class SystemTrayView : public views::View {
 
  private:
   // Tracks the views created in the last call to CreateItemViews().
-  std::map<SystemTrayItem::UmaType, views::View*> tray_item_view_map_;
+  std::map<SystemTrayItemUmaType, views::View*> tray_item_view_map_;
 
   std::unique_ptr<ui::EventHandler> time_to_click_recorder_;
   std::unique_ptr<ui::EventHandler> interacted_by_tap_recorder_;

ash/system/tray/test_system_tray_item.cc

@@ -12,9 +12,10 @@
 
 namespace ash {
 
-TestSystemTrayItem::TestSystemTrayItem() : TestSystemTrayItem(UMA_TEST) {}
+TestSystemTrayItem::TestSystemTrayItem()
+    : TestSystemTrayItem(SystemTrayItemUmaType::UMA_TEST) {}
 
-TestSystemTrayItem::TestSystemTrayItem(SystemTrayItem::UmaType uma_type)
+TestSystemTrayItem::TestSystemTrayItem(SystemTrayItemUmaType uma_type)
     : SystemTrayItem(AshTestBase::GetPrimarySystemTray(), uma_type),
       has_views_(true),
       views_are_visible_(true),

ash/system/tray/test_system_tray_item.h

@@ -16,7 +16,7 @@ namespace ash {
 class TestSystemTrayItem : public SystemTrayItem {
  public:
   TestSystemTrayItem();
-  explicit TestSystemTrayItem(SystemTrayItem::UmaType uma_type);
+  explicit TestSystemTrayItem(SystemTrayItemUmaType uma_type);
   ~TestSystemTrayItem() override;
 
   void set_has_views(bool has_views) { has_views_ = has_views; }

ash/system/tray/tray_detailed_view_unittest.cc

@@ -52,7 +52,8 @@ class TestDetailsView : public TrayDetailedView {
 class TestItem : public SystemTrayItem {
  public:
   TestItem()
-      : SystemTrayItem(AshTestBase::GetPrimarySystemTray(), UMA_TEST),
+      : SystemTrayItem(AshTestBase::GetPrimarySystemTray(),
+                       SystemTrayItemUmaType::UMA_TEST),
         tray_view_(nullptr),
         default_view_(nullptr),
         detailed_view_(nullptr),

ash/system/tray/tray_image_item.cc

@@ -18,7 +18,7 @@ namespace ash {
 
 TrayImageItem::TrayImageItem(SystemTray* system_tray,
                              const gfx::VectorIcon& icon,
-                             UmaType uma_type)
+                             SystemTrayItemUmaType uma_type)
     : SystemTrayItem(system_tray, uma_type),
       icon_(icon),
       icon_color_(kTrayIconColor),

ash/system/tray/tray_image_item.h

@@ -26,7 +26,7 @@ class ASH_EXPORT TrayImageItem : public SystemTrayItem {
  public:
   TrayImageItem(SystemTray* system_tray,
                 const gfx::VectorIcon& icon,
-                UmaType uma_type);
+                SystemTrayItemUmaType uma_type);
   ~TrayImageItem() override;
 
   views::View* tray_view();

ash/system/tray_accessibility.cc

@@ -458,7 +458,7 @@ void AccessibilityDetailedView::ShowHelp() {
 TrayAccessibility::TrayAccessibility(SystemTray* system_tray)
     : TrayImageItem(system_tray,
                     kSystemTrayAccessibilityIcon,
-                    UMA_ACCESSIBILITY),
+                    SystemTrayItemUmaType::UMA_ACCESSIBILITY),
       default_(nullptr),
       detailed_menu_(nullptr),
       tray_icon_visible_(false),

ash/system/tray_caps_lock.cc

@@ -133,7 +133,9 @@ class CapsLockDefaultView : public ActionableView {
 };
 
 TrayCapsLock::TrayCapsLock(SystemTray* system_tray)
-    : TrayImageItem(system_tray, kSystemTrayCapsLockIcon, UMA_CAPS_LOCK),
+    : TrayImageItem(system_tray,
+                    kSystemTrayCapsLockIcon,
+                    SystemTrayItemUmaType::UMA_CAPS_LOCK),
       default_(nullptr),
       caps_lock_enabled_(IsCapsLockEnabled()) {
   Shell::Get()->ime_controller()->AddObserver(this);

ash/system/tray_tracing.cc

@@ -72,7 +72,9 @@ class DefaultTracingView : public ActionableView {
 // ash::TrayTracing
 
 TrayTracing::TrayTracing(SystemTray* system_tray)
-    : TrayImageItem(system_tray, kSystemTrayTracingIcon, UMA_TRACING) {
+    : TrayImageItem(system_tray,
+                    kSystemTrayTracingIcon,
+                    SystemTrayItemUmaType::UMA_TRACING) {
   DCHECK(system_tray);
   Shell::Get()->system_tray_model()->tracing()->AddObserver(this);
 }

ash/system/unified/accessibility_feature_pod_controller.cc

@@ -39,4 +39,8 @@ void AccessibilityFeaturePodController::OnIconPressed() {
   tray_controller_->ShowAccessibilityDetailedView();
 }
 
+SystemTrayItemUmaType AccessibilityFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_ACCESSIBILITY;
+}
+
 }  // namespace ash

ash/system/unified/accessibility_feature_pod_controller.h

@@ -24,6 +24,7 @@ class ASH_EXPORT AccessibilityFeaturePodController
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
  private:
   // Unowned.

ash/system/unified/feature_pod_controller_base.h

@@ -6,6 +6,7 @@
 #define ASH_SYSTEM_UNIFIED_FEATURE_POD_CONTROLLER_BASE_H_
 
 #include "ash/ash_export.h"
+#include "ash/system/tray/system_tray_item_uma_type.h"
 
 namespace ash {
 
@@ -32,6 +33,10 @@ class ASH_EXPORT FeaturePodControllerBase {
   // If the feature pod has a detailed view, it is expected to show the detailed
   // view. Defaults to OnIconPressed().
   virtual void OnLabelPressed();
+
+  // Return histogram value for Ash.SystemMenu.DefaultView.VisibleRows. If the
+  // button is not recorded, UMA_NOT_RECORDED will be used.
+  virtual SystemTrayItemUmaType GetUmaType() const = 0;
 };
 
 }  // namespace ash

ash/system/unified/feature_pods_container_view_unittest.cc

@@ -31,6 +31,9 @@ class FeaturePodsContainerViewTest : public AshTestBase,
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override { return nullptr; }
   void OnIconPressed() override {}
+  SystemTrayItemUmaType GetUmaType() const override {
+    return SystemTrayItemUmaType::UMA_TEST;
+  }
 
   // views::ViewObserver:
   void OnViewPreferredSizeChanged(views::View* observed_view) override {

ash/system/unified/quiet_mode_feature_pod_controller.cc

@@ -37,6 +37,10 @@ void QuietModeFeaturePodController::OnIconPressed() {
   message_center->SetQuietMode(!is_quiet_mode);
 }
 
+SystemTrayItemUmaType QuietModeFeaturePodController::GetUmaType() const {
+  return SystemTrayItemUmaType::UMA_NOT_RECORDED;
+}
+
 void QuietModeFeaturePodController::OnQuietModeChanged(bool in_quiet_mode) {
   button_->SetVectorIcon(in_quiet_mode
                              ? kNotificationCenterDoNotDisturbOnIcon

ash/system/unified/quiet_mode_feature_pod_controller.h

@@ -25,6 +25,7 @@ class QuietModeFeaturePodController
   // FeaturePodControllerBase:
   FeaturePodButton* CreateButton() override;
   void OnIconPressed() override;
+  SystemTrayItemUmaType GetUmaType() const override;
 
   // message_center::MessageCenterObserver:
   void OnQuietModeChanged(bool in_quiet_mode) override;

ash/system/unified/unified_system_tray_controller.cc

@@ -24,8 +24,10 @@
 #include "ash/system/night_light/night_light_feature_pod_controller.h"
 #include "ash/system/rotation/rotation_lock_feature_pod_controller.h"
 #include "ash/system/tray/system_tray_controller.h"
+#include "ash/system/tray/system_tray_item_uma_type.h"
 #include "ash/system/unified/accessibility_feature_pod_controller.h"
 #include "ash/system/unified/detailed_view_controller.h"
+#include "ash/system/unified/feature_pod_button.h"
 #include "ash/system/unified/feature_pod_controller_base.h"
 #include "ash/system/unified/quiet_mode_feature_pod_controller.h"
 #include "ash/system/unified/unified_system_tray_model.h"
@@ -262,7 +264,17 @@ void UnifiedSystemTrayController::InitFeaturePods() {
 void UnifiedSystemTrayController::AddFeaturePodItem(
     std::unique_ptr<FeaturePodControllerBase> controller) {
   DCHECK(unified_view_);
-  unified_view_->AddFeaturePodButton(controller->CreateButton());
+  FeaturePodButton* button = controller->CreateButton();
+
+  // Record DefaultView.VisibleRows UMA.
+  SystemTrayItemUmaType uma_type = controller->GetUmaType();
+  if (uma_type != SystemTrayItemUmaType::UMA_NOT_RECORDED &&
+      button->visible_preferred()) {
+    UMA_HISTOGRAM_ENUMERATION("Ash.SystemMenu.DefaultView.VisibleRows",
+                              uma_type, SystemTrayItemUmaType::UMA_COUNT);
+  }
+
+  unified_view_->AddFeaturePodButton(button);
   feature_pod_controllers_.push_back(std::move(controller));
 }
 

ash/system/update/tray_update.cc

@@ -131,7 +131,9 @@ class TrayUpdate::UpdateView : public ActionableView {
 };
 
 TrayUpdate::TrayUpdate(SystemTray* system_tray)
-    : TrayImageItem(system_tray, kSystemTrayUpdateIcon, UMA_UPDATE),
+    : TrayImageItem(system_tray,
+                    kSystemTrayUpdateIcon,
+                    SystemTrayItemUmaType::UMA_UPDATE),
       model_(Shell::Get()->system_tray_model()->update_model()) {
   model_->AddObserver(this);
 }

ash/system/user/tray_user.cc

@@ -47,7 +47,8 @@ views::ImageView* CreateIcon() {
 namespace ash {
 
 TrayUser::TrayUser(SystemTray* system_tray)
-    : SystemTrayItem(system_tray, UMA_USER), scoped_session_observer_(this) {}
+    : SystemTrayItem(system_tray, SystemTrayItemUmaType::UMA_USER),
+      scoped_session_observer_(this) {}
 
 TrayUser::~TrayUser() = default;