[Sync] Clean up UIModelWorkerTest.

components/sync/driver/glue/ui_model_worker_unittest.cc

Index: components/sync/driver/glue/ui_model_worker_unittest.cc
diff --git a/components/sync/driver/glue/ui_model_worker_unittest.cc b/components/sync/driver/glue/ui_model_worker_unittest.cc
index 525df6e710c820fec987d3dd29e679295a036db7..2c83554c25b8938b46499edbfca9a60610d8a873 100644
--- a/components/sync/driver/glue/ui_model_worker_unittest.cc
+++ b/components/sync/driver/glue/ui_model_worker_unittest.cc
@@ -4,14 +4,11 @@
 
 #include "components/sync/driver/glue/ui_model_worker.h"
 
-#include <memory>
-
 #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/synchronization/waitable_event.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -19,83 +16,47 @@
 namespace syncer {
 namespace {
 
-class UIModelWorkerVisitor {
- public:
-  UIModelWorkerVisitor(base::WaitableEvent* was_run, bool quit_loop)
-      : quit_loop_when_run_(quit_loop), was_run_(was_run) {}
-  virtual ~UIModelWorkerVisitor() {}
-
-  virtual SyncerError DoWork() {
-    was_run_->Signal();
-    if (quit_loop_when_run_)
-      base::MessageLoop::current()->QuitWhenIdle();
-    return SYNCER_OK;
-  }
-
- private:
-  bool quit_loop_when_run_;
-  base::WaitableEvent* was_run_;
-  DISALLOW_COPY_AND_ASSIGN(UIModelWorkerVisitor);
-};
-
-// A fake syncer that only interacts with its model safe worker.
-class FakeSyncer {
- public:
-  explicit FakeSyncer(UIModelWorker* worker) : worker_(worker) {}
-  ~FakeSyncer() {}
-
-  void SyncShare(UIModelWorkerVisitor* visitor) {
-    // We wait until the callback is executed. So it is safe to use Unretained.
-    WorkCallback c =
-        base::Bind(&UIModelWorkerVisitor::DoWork, base::Unretained(visitor));
-    worker_->DoWorkAndWaitUntilDone(c);
-  }
+// 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;
+}
 
- private:
-  scoped_refptr<UIModelWorker> worker_;
-  DISALLOW_COPY_AND_ASSIGN(FakeSyncer);
-};
+// 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()
-      : faux_syncer_thread_("FauxSyncerThread"),
-        faux_core_thread_("FauxCoreThread") {}
-
-  void SetUp() override {
-    faux_syncer_thread_.Start();
-    bmw_ = new UIModelWorker(base::ThreadTaskRunnerHandle::Get(), nullptr);
-    syncer_.reset(new FakeSyncer(bmw_.get()));
+  SyncUIModelWorkerTest() : sync_thread_("SyncThreadForTest") {
+    sync_thread_.Start();
+    worker_ = new UIModelWorker(base::ThreadTaskRunnerHandle::Get(), nullptr);
   }
 
-  FakeSyncer* syncer() { return syncer_.get(); }
-  UIModelWorker* bmw() { return bmw_.get(); }
-  base::Thread* core_thread() { return &faux_core_thread_; }
-  base::Thread* syncer_thread() { return &faux_syncer_thread_; }
+  void PostWorkToSyncThread(WorkCallback work) {
+    sync_thread_.task_runner()->PostTask(
+        FROM_HERE,
+        base::Bind(base::IgnoreResult(&UIModelWorker::DoWorkAndWaitUntilDone),
+                   worker_, work));
+  }
 
  private:
-  base::MessageLoop faux_ui_loop_;
-  base::Thread faux_syncer_thread_;
-  base::Thread faux_core_thread_;
-  scoped_refptr<UIModelWorker> bmw_;
-  std::unique_ptr<FakeSyncer> syncer_;
+  base::MessageLoop ui_loop_;
+  base::Thread sync_thread_;
+  scoped_refptr<UIModelWorker> worker_;
 };
 
 TEST_F(SyncUIModelWorkerTest, ScheduledWorkRunsOnUILoop) {
-  base::WaitableEvent v_was_run(
-      base::WaitableEvent::ResetPolicy::AUTOMATIC,
-      base::WaitableEvent::InitialState::NOT_SIGNALED);
-  std::unique_ptr<UIModelWorkerVisitor> v(
-      new UIModelWorkerVisitor(&v_was_run, true));
-
-  syncer_thread()->task_runner()->PostTask(
-      FROM_HERE,
-      base::Bind(&FakeSyncer::SyncShare, base::Unretained(syncer()), v.get()));
-
-  // We are on the UI thread, so run our loop to process the
-  // (hopefully) scheduled task from a SyncShare invocation.
-  base::RunLoop().Run();
-  syncer_thread()->Stop();
+  base::RunLoop run_loop;
+  PostWorkToSyncThread(ClosureToWorkCallback(run_loop.QuitClosure()));
+  // This won't quit until the QuitClosure is run.
+  run_loop.Run();
 }
 
 }  // namespace