Added histograms for tracking new user's priority prefs sync time and results.

chrome/browser/chromeos/login/screens/user_image_screen.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 "chrome/browser/chromeos/login/screens/user_image_screen.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 107 matching lines @@
   if (accept_photo_after_decoding_)
     OnImageAccepted();
 }
 
 void UserImageScreen::OnDecodeImageFailed() {
   NOTREACHED() << "Failed to decode PNG image from WebUI";
 }
 
 void UserImageScreen::OnInitialSync(bool local_image_updated) {
   DCHECK(sync_timer_);
+  ReportSyncResult(SyncResult::SUCCEED);
   if (!local_image_updated) {
     sync_timer_.reset();
     GetSyncObserver()->RemoveObserver(this);
     if (is_screen_ready_)
       HideCurtain();
     return;
   }
   ExitScreen();
 }
 
 void UserImageScreen::OnSyncTimeout() {
+  ReportSyncResult(SyncResult::TIMED_OUT);
   sync_timer_.reset();
   GetSyncObserver()->RemoveObserver(this);
   if (is_screen_ready_)
     HideCurtain();
 }
 
 bool UserImageScreen::IsWaitingForSync() const {
   return sync_timer_.get() && sync_timer_->IsRunning();
 }
 
@@ skipping 105 matching lines @@
     policy_registrar_->Observe(
         policy::key::kUserAvatarImage,
         base::Bind(&UserImageScreen::OnUserImagePolicyChanged,
                    base::Unretained(this)));
   } else {
     NOTREACHED();
   }
 
   if (GetUser()->CanSyncImage()) {
     if (UserImageSyncObserver* sync_observer = GetSyncObserver()) {
+      sync_waiting_start_time_ = base::Time::Now();
       // We have synced image already.
       if (sync_observer->is_synced()) {
+        ReportSyncResult(SyncResult::SUCCEED);
         ExitScreen();
         return;
       }
       sync_observer->AddObserver(this);
       sync_timer_.reset(new base::Timer(
             FROM_HERE,
             base::TimeDelta::FromSeconds(kSyncTimeoutSeconds),
             base::Bind(&UserImageScreen::OnSyncTimeout, base::Unretained(this)),
             false));
       sync_timer_->Reset();
@@ skipping 59 matching lines @@
 }
 
 void UserImageScreen::ExitScreen() {
   policy_registrar_.reset();
   sync_timer_.reset();
   if (UserImageSyncObserver* sync_observer = GetSyncObserver())
     sync_observer->RemoveObserver(this);
   Finish(BaseScreenDelegate::USER_IMAGE_SELECTED);
 }
 
+void UserImageScreen::ReportSyncResult(SyncResult timed_out) const {
+  base::TimeDelta duration = base::Time::Now() - sync_waiting_start_time_;
+  UMA_HISTOGRAM_TIMES("Login.NewUserPriorityPrefsSyncTime", duration);
+  UMA_HISTOGRAM_ENUMERATION("Login.NewUserPriorityPrefsSyncResult",
+                            static_cast<int>(timed_out), 2);

[Ilya Sherman, 2015/05/15 17:36:40]

nit: Maybe write this as below?  I'm not too happy about the hardcoded 2 -- if
the SyncResult enum were ever expanded, this code path would silently break.

UMA_HISTOGRAM_BOOLEAN("Login.NewUserPriorityPrefsSyncResult",
                      timed_out == SyncResult::TIMED_OUT);

[dzhioev (left Google), 2015/05/15 20:36:50]

I've added |COUNT| element to the enum, and use it here instead of hardcoded
|2|.

+}
+
 }  // namespace chromeos