Introduce HistoryClient interface

chrome/browser/history/chrome_history_client_factory.cc

Index: chrome/browser/history/chrome_history_client_factory.cc
diff --git a/chrome/browser/history/chrome_history_client_factory.cc b/chrome/browser/history/chrome_history_client_factory.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5e89dd686387c9930452a8311226a11b89784341
--- /dev/null
+++ b/chrome/browser/history/chrome_history_client_factory.cc
@@ -0,0 +1,45 @@
+// 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/history/chrome_history_client_factory.h"
+
+#include "chrome/browser/history/chrome_history_client.h"
+#include "chrome/browser/profiles/incognito_helpers.h"
+#include "chrome/browser/profiles/profile.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+
+// static
+ChromeHistoryClient* ChromeHistoryClientFactory::GetForProfile(
+    Profile* profile) {
+  return static_cast<ChromeHistoryClient*>(
+      GetInstance()->GetServiceForBrowserContext(profile, true));
+}
+
+// static
+ChromeHistoryClientFactory* ChromeHistoryClientFactory::GetInstance() {
+  return Singleton<ChromeHistoryClientFactory>::get();
+}
+
+ChromeHistoryClientFactory::ChromeHistoryClientFactory()
+    : BrowserContextKeyedServiceFactory(
+          "ChromeHistoryClient",
+          BrowserContextDependencyManager::GetInstance()) {
+}
+
+ChromeHistoryClientFactory::~ChromeHistoryClientFactory() {
+}
+
+KeyedService* ChromeHistoryClientFactory::BuildServiceInstanceFor(
+    content::BrowserContext* context) const {
+  return new ChromeHistoryClient();
+}
+
+content::BrowserContext* ChromeHistoryClientFactory::GetBrowserContextToUse(
+    content::BrowserContext* context) const {
+  return chrome::GetBrowserContextRedirectedInIncognito(context);
+}
+
+bool ChromeHistoryClientFactory::ServiceIsNULLWhileTesting() const {
+  return true;
+}