Add login time metric for chromeos.

chrome/browser/chromeos/browser_notification_observers.cc

 // Copyright (c) 2010 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/browser_notification_observers.h"
 
 #include <string>
 
 #include "base/file_util.h"
 #include "chrome/browser/chrome_thread.h"
@@ skipping 10 matching lines @@
 
 InitialTabNotificationObserver::~InitialTabNotificationObserver() {
 }
 
 void InitialTabNotificationObserver::Observe(
     NotificationType type,
     const NotificationSource& source,
     const NotificationDetails& details) {
   // Only log for first tab to render.  Make sure this is only done once.
   if (type == NotificationType::LOAD_START && num_tabs_.GetNext() == 0) {
-    // If we can't post it, it doesn't matter.
+    // Post difference between first tab and login succeess time as login time.
+    UMA_HISTOGRAM_TIMES("BootTime.Login",
+                        base::Time::NowFromSystemTime() - login_success_time_);
+    // Post chrome first render stat.
     BootTimesLoader::RecordCurrentStats("chrome-first-render");
     registrar_.Remove(this, NotificationType::LOAD_START,
                       NotificationService::AllSources());
   }
 }
 
 LogLoginSuccessObserver::LogLoginSuccessObserver() {
   registrar_.Add(this, NotificationType::LOGIN_AUTHENTICATION,
                  NotificationService::AllSources());
 }
 
 LogLoginSuccessObserver::~LogLoginSuccessObserver() {
 }
 
 void LogLoginSuccessObserver::Observe(NotificationType type,
                                    const NotificationSource& source,
                                    const NotificationDetails& details) {
   DCHECK(type == NotificationType::LOGIN_AUTHENTICATION);
   Details<AuthenticationNotificationDetails> auth_details(details);
   if (auth_details->success()) {
-    // If we can't post it, it doesn't matter.
+    InitialTabNotificationObserver::Get()->SetLoginSuccessTime();
     BootTimesLoader::RecordCurrentStats("login-successful");
     registrar_.Remove(this, NotificationType::LOGIN_AUTHENTICATION,
                       NotificationService::AllSources());
   }
 }
 
 }  // namespace chromeos