[iOS] Add FakeSyncService and factory for testing

ios/public/test/test_keyed_service_provider.cc

+// Copyright 2015 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 "ios/public/test/test_keyed_service_provider.h"
+
+#include "base/memory/singleton.h"
+#include "components/keyed_service/ios/browser_state_dependency_manager.h"
+#include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
+#include "ios/public/provider/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/public/test/fake_sync_service.h"
+
+namespace {
+
+class FakeSyncServiceFactory : public BrowserStateKeyedServiceFactory {

[sdefresne, 2015/06/08 16:24:17]

nit: move this to fake_sync_service_factory.{h,cc}

+ public:
+  // Returns the singleton FakeSyncServiceFactory instance.
+  static FakeSyncServiceFactory* GetInstance() {
+    return Singleton<FakeSyncServiceFactory>::get();
+  }
+
+  // Returns the FakeSyncServiceFactory associated to |browser_state|.
+  static FakeSyncService* GetForBrowserState(web::BrowserState* browser_state) {

[sdefresne, 2015/06/08 16:24:17]

nit: s/FakeSyncService*/sync_driver::SyncService*/

+    return static_cast<FakeSyncService*>(
+        FakeSyncServiceFactory::GetInstance()->GetServiceForBrowserState(
+            browser_state, true));
+  }
+
+ private:
+  friend struct DefaultSingletonTraits<FakeSyncServiceFactory>;
+
+  // BrowserStateKeyedServiceFactory implementation:
+  KeyedService* BuildServiceInstanceFor(
+      web::BrowserState* context) const override {
+    return new FakeSyncService;
+  }
+
+  FakeSyncServiceFactory()
+      : BrowserStateKeyedServiceFactory(
+            "FakeSyncService",
+            BrowserStateDependencyManager::GetInstance()) {}
+  ~FakeSyncServiceFactory() override {}
+
+  DISALLOW_COPY_AND_ASSIGN(FakeSyncServiceFactory);
+};
+
+}  // namespace
+
+namespace ios {
+
+TestKeyedServiceProvider::TestKeyedServiceProvider() {
+}
+
+TestKeyedServiceProvider::~TestKeyedServiceProvider() {
+}
+
+KeyedServiceBaseFactory* TestKeyedServiceProvider::GetSyncServiceFactory() {
+  return FakeSyncServiceFactory::GetInstance();
+}
+
+sync_driver::SyncService*
+TestKeyedServiceProvider::GetSyncServiceForBrowserState(
+    ChromeBrowserState* browser_state) {
+  return FakeSyncServiceFactory::GetForBrowserState(browser_state);
+}
+
+}  // namespace ios