Fix up compositor mocking.

ui/gfx/test/gfx_test_utils.cc

+// Copyright (c) 2011 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 "ui/gfx/test/gfx_test_utils.h"
+
+#if defined(VIEWS_COMPOSITOR)
+#include "ui/gfx/compositor/compositor.h"
+#include "ui/gfx/compositor/test_compositor.h"
+#endif
+
+namespace ui {
+namespace gfx_test_utils {
+
+void SetupTestCompositor() {
+#if defined(VIEWS_COMPOSITOR)
+  // Use a mock compositor that noops draws.
+  ui::Compositor::set_compositor_factory_for_testing(
+      ui::TestCompositor::Create);
+#endif
+}
+
+}  // namespace gfx_test_utils
+}  // namespace ui