Fix CompositorResizeLock to do something.

ui/compositor/test/fake_compositor_lock.h

+// Copyright 2017 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 UI_COMPOSITOR_FAKE_COMPOSITOR_LOCK_H_
+#define UI_COMPOSITOR_FAKE_COMPOSITOR_LOCK_H_
+
+#include "ui/compositor/compositor_lock.h"
+
+namespace ui {
+
+class FakeCompositorLock : public CompositorLock {
+ public:
+  explicit FakeCompositorLock(CompositorLockClient* client,
+                              CompositorLockDelegate* delegate,
+                              base::SequencedTaskRunner* task_runner,
+                              base::TimeDelta timeout);
+
+  // Allow tests to cause the lock to timeout.
+  using CompositorLock::TimeoutLock;
+
+ private:
+  ~FakeCompositorLock() {}
+};
+
+}  // namespace
+
+#endif  // UI_COMPOSITOR_FAKE_COMPOSITOR_LOCK_H_