[iOS] Add FakeSyncService and factory for testing

ios/public/test/fake_sync_service.h

+// 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.
+
+#ifndef IOS_PUBLIC_TEST_FAKE_SYNC_SERVICE_H_
+#define IOS_PUBLIC_TEST_FAKE_SYNC_SERVICE_H_
+
+#include "components/keyed_service/core/keyed_service.h"
+#include "components/sync_driver/sync_service.h"
+#include "google_apis/gaia/google_service_auth_error.h"
+#include "ios/public/test/fake_sync_service.h"
+
+// Fake implementation of sync_driver::SyncService, used for testing.
+class FakeSyncService : public sync_driver::SyncService, public KeyedService {

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

Could you get this moved into //components/sync_driver? I think it would make
sense to have the fake implementation living there. If it cannot be a
KeyedService then at least you can use a small wrapper in the
FakeSyncServiceFactory, something like:

class FakeSyncServiceWrapper : public KeyedService {
 public:
  FakeSyncServiceWrapper() {}
  sync_driver::SyncService* sync_service() {
    return &fake_sync_service_;
  }
 private:
  FakeSyncService fake_sync_service_;
};

// static
sync_driver::SyncService* FakeSyncServiceFactory::GetForInstance(
    web::BrowserState* browser_state) {
  return static_cast<FakeSyncServiceWrapper*>(
      GetInstance()->GetServiceForBrowserState(
          browser_state, true))->sync_service();
}

I'm fine if this is done in a followup CL with a tracking crbug.

+ public:
+  FakeSyncService();
+  ~FakeSyncService() override;
+
+ private:
+  // sync_driver::SyncService:
+  bool HasSyncSetupCompleted() const override;
+  bool IsSyncActive() const override;
+  syncer::ModelTypeSet GetActiveDataTypes() const override;
+  void AddObserver(sync_driver::SyncServiceObserver* observer) override;
+  void RemoveObserver(sync_driver::SyncServiceObserver* observer) override;
+  bool HasObserver(
+      const sync_driver::SyncServiceObserver* observer) const override;
+  bool IsSyncEnabledAndLoggedIn() override;
+  void DisableForUser() override;
+  void StopAndSuppress() override;
+  void UnsuppressAndStart() override;
+  syncer::ModelTypeSet GetPreferredDataTypes() const override;
+  void OnUserChoseDatatypes(bool sync_everything,
+                            syncer::ModelTypeSet chosen_types) override;
+  void SetSyncSetupCompleted() override;
+  bool FirstSetupInProgress() const override;
+  void SetSetupInProgress(bool setup_in_progress) override;
+  bool setup_in_progress() const override;
+  bool ConfigurationDone() const override;
+  const GoogleServiceAuthError& GetAuthError() const override;
+  bool HasUnrecoverableError() const override;
+  bool backend_initialized() const override;
+  bool IsPassphraseRequiredForDecryption() const override;
+  base::Time GetExplicitPassphraseTime() const override;
+  bool IsUsingSecondaryPassphrase() const override;
+  void EnableEncryptEverything() override;
+  void SetEncryptionPassphrase(const std::string& passphrase,
+                               PassphraseType type) override;
+  bool SetDecryptionPassphrase(const std::string& passphrase) override;
+
+  // sync_driver::DataTypeEncryptionHandler:
+  bool IsPassphraseRequired() const override;
+  syncer::ModelTypeSet GetEncryptedDataTypes() const override;
+
+  GoogleServiceAuthError error_;
+};
+
+#endif  // IOS_PUBLIC_TEST_FAKE_SYNC_SERVICE_H_