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

ash/metrics/user_metrics_recorder.cc

 // Copyright 2013 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/metrics/user_metrics_recorder.h"
 
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/shelf_item_types.h"
 #include "ash/common/shelf/shelf_model.h"
 #include "ash/common/shell_window_ids.h"
@@ skipping 485 matching lines @@
       base::RecordAction(
           base::UserMetricsAction("StatusArea_Network_ConnectionDetails"));
       break;
     case UMA_STATUS_AREA_SHOW_VPN_CONNECTION_DETAILS:
       base::RecordAction(
           base::UserMetricsAction("StatusArea_VPN_ConnectionDetails"));
       break;
     case UMA_STATUS_AREA_SIGN_OUT:
       base::RecordAction(base::UserMetricsAction("StatusArea_SignOut"));
       break;
+    case UMA_STATUS_AREA_UPDATE_DEFAULT_CLICKED:
+      base::RecordAction(
+          base::UserMetricsAction("StatusArea_Update_Default_Clicked"));

[tdanderson, 2016/07/07 21:36:43]

nit: consider dropping "_Clicked" from the action name to be consistent with
other _CLICKED cases (see line 510 for example)

Also consider dropping "default" from the name since it's not needed for
disambiguation and I don't see that naming convention used elsewhere in this
file.

[bruthig, 2016/07/08 17:49:44]

Acknowledged.

+      break;
     case UMA_STATUS_AREA_VPN_ADD_BUILT_IN_CLICKED:
       base::RecordAction(base::UserMetricsAction("StatusArea_VPN_AddBuiltIn"));
       break;
     case UMA_STATUS_AREA_VPN_ADD_THIRD_PARTY_CLICKED:
       base::RecordAction(
           base::UserMetricsAction("StatusArea_VPN_AddThirdParty"));
       break;
     case UMA_STATUS_AREA_VPN_DISCONNECT_CLICKED:
       base::RecordAction(base::UserMetricsAction("StatusArea_VPN_Disconnect"));
       break;
@@ skipping 120 matching lines @@
   return IsUserActive() && !IsKioskModeActive();
 }
 
 void UserMetricsRecorder::StartTimer() {
   timer_.Start(FROM_HERE,
                base::TimeDelta::FromSeconds(kAshPeriodicMetricsTimeInSeconds),
                this, &UserMetricsRecorder::RecordPeriodicMetrics);
 }
 
 }  // namespace ash