[Sync] Move sync's ModelSafeWorker implementations to engine/.

components/sync/driver/glue/ui_model_worker_unittest.cc

-// Copyright (c) 2012 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 "components/sync/driver/glue/ui_model_worker.h"
-
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/location.h"
-#include "base/memory/ref_counted.h"
-#include "base/run_loop.h"
-#include "base/threading/thread.h"
-#include "base/threading/thread_task_runner_handle.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace syncer {
-namespace {
-
-// Makes a Closure into a WorkCallback.
-// Does |work| and checks that we're on the |thread_verifier| thread.
-SyncerError DoWork(
-    const scoped_refptr<base::SingleThreadTaskRunner>& thread_verifier,
-    base::Closure work) {
-  DCHECK(thread_verifier->BelongsToCurrentThread());
-  work.Run();
-  return SYNCER_OK;
-}
-
-// Converts |work| to a WorkCallback that will verify that it's run on the
-// thread it was constructed on.
-WorkCallback ClosureToWorkCallback(base::Closure work) {
-  return base::Bind(&DoWork, base::ThreadTaskRunnerHandle::Get(), work);
-}
-
-class SyncUIModelWorkerTest : public testing::Test {
- public:
-  SyncUIModelWorkerTest() : sync_thread_("SyncThreadForTest") {
-    sync_thread_.Start();
-    worker_ = new UIModelWorker(base::ThreadTaskRunnerHandle::Get());
-  }
-
-  void PostWorkToSyncThread(WorkCallback work) {
-    sync_thread_.task_runner()->PostTask(
-        FROM_HERE,
-        base::Bind(base::IgnoreResult(&UIModelWorker::DoWorkAndWaitUntilDone),
-                   worker_, work));
-  }
-
- private:
-  base::MessageLoop ui_loop_;
-  base::Thread sync_thread_;
-  scoped_refptr<UIModelWorker> worker_;
-};
-
-TEST_F(SyncUIModelWorkerTest, ScheduledWorkRunsOnUILoop) {
-  base::RunLoop run_loop;
-  PostWorkToSyncThread(ClosureToWorkCallback(run_loop.QuitClosure()));
-  // This won't quit until the QuitClosure is run.
-  run_loop.Run();
-}
-
-}  // namespace
-}  // namespace syncer