Adding an IO Data and keyed service to previews/

chrome/browser/previews/previews_service_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/previews/previews_service_factory.h"
+
+#include "chrome/browser/previews/previews_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "content/public/browser/browser_context.h"
+
+namespace {
+
+base::LazyInstance<PreviewsServiceFactory> g_previews_factory =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+// static
+PreviewsService* PreviewsServiceFactory::GetForProfile(Profile* profile) {
+  DCHECK_NE(profile->GetProfileType(), Profile::INCOGNITO_PROFILE);
+  return static_cast<PreviewsService*>(
+      GetInstance()->GetServiceForBrowserContext(profile, true));
+}
+
+// static
+PreviewsServiceFactory* PreviewsServiceFactory::GetInstance() {
+  return g_previews_factory.Pointer();
+}
+
+PreviewsServiceFactory::PreviewsServiceFactory()
+    : BrowserContextKeyedServiceFactory(
+          "PreviewsService",
+          BrowserContextDependencyManager::GetInstance()) {}
+
+PreviewsServiceFactory::~PreviewsServiceFactory() {}
+
+KeyedService* PreviewsServiceFactory::BuildServiceInstanceFor(
+    content::BrowserContext* context) const {
+  return new PreviewsService();
+}