Added UMA metrics for the system update UI in the status area.

ash/common/system/update/tray_update.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/update/tray_update.h"
 
+#include "ash/common/metrics/user_metrics_action.h"
 #include "ash/common/system/tray/fixed_sized_image_view.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/wm_shell.h"
 #include "ash/system/tray/system_tray.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
@@ skipping 50 matching lines @@
     AddChildView(new views::Label(label));
     SetAccessibleName(label);
   }
 
   ~UpdateView() override {}
 
  private:
   // Overridden from ActionableView.
   bool PerformAction(const ui::Event& event) override {
     WmShell::Get()->system_tray_delegate()->RequestRestartForUpdate();
+    WmShell::Get()->RecordUserMetricsAction(
+        UMA_STATUS_AREA_OS_UPDATE_DEFAULT_SELECTED);
     return true;
   }
 
   DISALLOW_COPY_AND_ASSIGN(UpdateView);
 };
 
 }  // namespace
 
 TrayUpdate::TrayUpdate(SystemTray* system_tray)
     : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_UPDATE) {
@@ skipping 15 matching lines @@
   WmShell::Get()->system_tray_delegate()->GetSystemUpdateInfo(&info);
   return info.update_required ? new UpdateView(info) : nullptr;
 }
 
 void TrayUpdate::OnUpdateRecommended(const UpdateInfo& info) {
   SetImageFromResourceId(DecideResource(info.severity, false));
   tray_view()->SetVisible(true);
 }
 
 }  // namespace ash