Revert of [Sync] Refactor ModelSafeWorker::DoWorkAndWaitUntilDone() to avoid code duplication.

components/sync/base/scoped_event_signal_unittest.cc

Index: components/sync/base/scoped_event_signal_unittest.cc
diff --git a/components/sync/base/scoped_event_signal_unittest.cc b/components/sync/base/scoped_event_signal_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fe65b4b950e3ce73cd8fd664bee252f7df109a4a
--- /dev/null
+++ b/components/sync/base/scoped_event_signal_unittest.cc
@@ -0,0 +1,84 @@
+// Copyright 2016 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/base/scoped_event_signal.h"
+
+#include <memory>
+#include <utility>
+
+#include "base/synchronization/waitable_event.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace syncer {
+
+TEST(ScopedEventSignalTest, SignalAtEndOfScope) {
+  base::WaitableEvent event(base::WaitableEvent::ResetPolicy::MANUAL,
+                            base::WaitableEvent::InitialState::NOT_SIGNALED);
+
+  {
+    ScopedEventSignal scoped_event_signal(&event);
+    EXPECT_FALSE(event.IsSignaled());
+  }
+
+  EXPECT_TRUE(event.IsSignaled());
+}
+
+TEST(ScopedEventSignalTest, MoveConstructor) {
+  base::WaitableEvent event(base::WaitableEvent::ResetPolicy::MANUAL,
+                            base::WaitableEvent::InitialState::NOT_SIGNALED);
+
+  {
+    ScopedEventSignal scoped_event_signal(&event);
+    EXPECT_FALSE(event.IsSignaled());
+
+    {
+      ScopedEventSignal other_scoped_event_signal(
+          std::move(scoped_event_signal));
+      EXPECT_FALSE(event.IsSignaled());
+    }
+
+    // |event| is signaled when |other_scoped_event_signal| is destroyed.
+    EXPECT_TRUE(event.IsSignaled());
+
+    event.Reset();
+  }
+
+  // |event| is not signaled when |scoped_signal_event| is destroyed.
+  EXPECT_FALSE(event.IsSignaled());
+}
+
+TEST(ScopedEventSignalTest, MoveAssignOperator) {
+  base::WaitableEvent event(base::WaitableEvent::ResetPolicy::MANUAL,
+                            base::WaitableEvent::InitialState::NOT_SIGNALED);
+
+  {
+    ScopedEventSignal scoped_event_signal_a(&event);
+    EXPECT_FALSE(event.IsSignaled());
+
+    {
+      base::WaitableEvent other_event(
+          base::WaitableEvent::ResetPolicy::MANUAL,
+          base::WaitableEvent::InitialState::NOT_SIGNALED);
+      ScopedEventSignal scoped_event_signal_b(&other_event);
+
+      // Move |scoped_event_signal_b| to |scoped_event_signal_c| because the
+      // assignment operator cannot be used on a ScopedEventSignal which is
+      // already associated with an event.
+      ScopedEventSignal scoped_event_signal_c(std::move(scoped_event_signal_b));
+
+      scoped_event_signal_b = std::move(scoped_event_signal_a);
+      EXPECT_FALSE(event.IsSignaled());
+    }
+
+    // |event| is signaled when |scoped_event_signal_b| is destroyed.
+    EXPECT_TRUE(event.IsSignaled());
+
+    event.Reset();
+  }
+
+  // |event| is not signaled when |scoped_signal_event_a| is destroyed.
+  EXPECT_FALSE(event.IsSignaled());
+}
+
+}  // namespace syncer