[Smart Lock] Add UMA metrics to measure duration of unlock.

chrome/browser/signin/easy_unlock_service_signin_chromeos.cc

 // Copyright 2014 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/signin/easy_unlock_service_signin_chromeos.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 78 matching lines @@
 EasyUnlockServiceSignin::UserData::UserData()
     : state(EasyUnlockServiceSignin::USER_DATA_STATE_INITIAL) {
 }
 
 EasyUnlockServiceSignin::UserData::~UserData() {}
 
 EasyUnlockServiceSignin::EasyUnlockServiceSignin(Profile* profile)
     : EasyUnlockService(profile),
       allow_cryptohome_backoff_(true),
       service_active_(false),
+      user_pod_last_focused_timestamp_(base::TimeTicks::Now()),
       weak_ptr_factory_(this) {
 }
 
 EasyUnlockServiceSignin::~EasyUnlockServiceSignin() {
 }
 
 EasyUnlockService::Type EasyUnlockServiceSignin::GetType() const {
   return EasyUnlockService::TYPE_SIGNIN;
 }
 
@@ skipping 61 matching lines @@
   return data->devices[device_index].wrapped_secret;
 }
 
 void EasyUnlockServiceSignin::RecordEasySignInOutcome(
     const std::string& user_id,
     bool success) const {
   DCHECK_EQ(GetUserEmail(), user_id);
 
   RecordEasyUnlockSigninEvent(
       success ? EASY_UNLOCK_SUCCESS : EASY_UNLOCK_FAILURE);
+  if (success) {
+    RecordEasyUnlockSigninDuration(
+        base::TimeTicks::Now() - user_pod_last_focused_timestamp_);
+  }
   DVLOG(1) << "Easy sign-in " << (success ? "success" : "failure");
 }
 
 void EasyUnlockServiceSignin::RecordPasswordLoginEvent(
     const std::string& user_id) const {
   // This happens during tests, where a user could log in without the user pod
   // being focused.
   if (GetUserEmail() != user_id)
     return;
 
@@ skipping 55 matching lines @@
 
 void EasyUnlockServiceSignin::OnScreenDidLock(
     ScreenlockBridge::LockHandler::ScreenType screen_type) {
   // In production code, the screen type should always be the signin screen; but
   // in tests, the screen type might be different.
   if (screen_type != ScreenlockBridge::LockHandler::SIGNIN_SCREEN)
     return;
 
   // Update initial UI is when the account picker on login screen is ready.
   ShowInitialUserState();
+  user_pod_last_focused_timestamp_ = base::TimeTicks::Now();
 }
 
 void EasyUnlockServiceSignin::OnScreenDidUnlock(
     ScreenlockBridge::LockHandler::ScreenType screen_type) {
   // In production code, the screen type should always be the signin screen; but
   // in tests, the screen type might be different.
   if (screen_type != ScreenlockBridge::LockHandler::SIGNIN_SCREEN)
     return;
 
   DisableAppWithoutResettingScreenlockState();
 
   Shutdown();
 }
 
 void EasyUnlockServiceSignin::OnFocusedUserChanged(const std::string& user_id) {
   if (user_id_ == user_id)
     return;
 
   // Setting or clearing the user_id may changed |IsAllowed| value, so in these
   // cases update the app state. Otherwise, it's enough to notify the app the
   // user data has been updated.
   bool should_update_app_state = user_id_.empty() != user_id.empty();
   user_id_ = user_id;
+  user_pod_last_focused_timestamp_ = base::TimeTicks::Now();
 
   ResetScreenlockState();
   ShowInitialUserState();
 
   if (should_update_app_state) {
     UpdateAppState();
   } else {
     NotifyUserUpdated();
   }
 
@@ skipping 67 matching lines @@
     return NULL;
 
   std::map<std::string, UserData*>::const_iterator it =
       user_data_.find(user_id_);
   if (it == user_data_.end())
     return NULL;
   if (it->second->state != USER_DATA_STATE_LOADED)
     return NULL;
   return it->second;
 }