Implement pin storage backend.

chrome/browser/chromeos/login/quick_unlock/pin_storage_factory.cc

+// Copyright 2016 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/quick_unlock/pin_storage_factory.h"
+
+#include "chrome/browser/chromeos/login/quick_unlock/pin_storage.h"
+#include "chrome/browser/profiles/profile.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+
+namespace chromeos {
+
+// static
+PinStorage* PinStorageFactory::GetForProfile(Profile* profile) {
+  return static_cast<PinStorage*>(
+      GetInstance()->GetServiceForBrowserContext(profile, true));
+}
+
+// static
+PinStorageFactory* PinStorageFactory::GetInstance() {
+  return base::Singleton<PinStorageFactory>::get();
+}
+
+PinStorageFactory::PinStorageFactory()
+    : BrowserContextKeyedServiceFactory(
+          "PinStorageFactory",
+          BrowserContextDependencyManager::GetInstance()) {}
+
+PinStorageFactory::~PinStorageFactory() {}
+
+KeyedService* PinStorageFactory::BuildServiceInstanceFor(
+    content::BrowserContext* context) const {
+  return new PinStorage(Profile::FromBrowserContext(context)->GetPrefs());
+}
+
+}  // namespace chromeos