Add policy for limiting the session length

chrome/browser/chromeos/session_length_limiter_factory.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/session_length_limiter_factory.h"
+
+#include "chrome/browser/chromeos/session_length_limiter.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_dependency_manager.h"
+#include "chrome/common/pref_names.h"
+
+namespace chromeos {
+
+// static
+SessionLengthLimiterFactory* SessionLengthLimiterFactory::GetInstance() {
+  return Singleton<SessionLengthLimiterFactory>::get();
+}
+
+SessionLengthLimiterFactory::SessionLengthLimiterFactory()
+    : ProfileKeyedServiceFactory("SessionLengthLimiter",
+                                 ProfileDependencyManager::GetInstance()) {
+}
+
+SessionLengthLimiterFactory::~SessionLengthLimiterFactory() {
+}
+
+ProfileKeyedService* SessionLengthLimiterFactory::BuildServiceInstanceFor(
+    Profile* profile) const {
+  return new SessionLengthLimiter(NULL, profile->GetPrefs());
+}
+
+void SessionLengthLimiterFactory::RegisterUserPrefs(PrefService* prefs) {
+  prefs->RegisterInt64Pref(prefs::kSessionStartTime,
+                           0,
+                           PrefService::UNSYNCABLE_PREF);
+  prefs->RegisterIntegerPref(prefs::kSessionLengthLimit,
+                             0,
+                             PrefService::UNSYNCABLE_PREF);
+}
+
+bool SessionLengthLimiterFactory::ServiceIsCreatedWithProfile() const {
+  return true;
+}
+
+bool SessionLengthLimiterFactory::ServiceIsNULLWhileTesting() const {
+  // Some tests replace the |PrefService| of the |TestingProfile| after the
+  // |SessionLengthLimiter| has been created, making its |Shutdown()| try to
+  // remove a |PrefChangeRegistrar| from a non-existent |PrefService|.
+  return true;
+}
+
+}  // namespace chromeos