cc: Add SwapPromiseManager and SurfaceSequenceGenerator.

cc/trees/surface_sequence_generator_unittest.cc

+// 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 "cc/trees/surface_sequence_generator.h"
+
+#include "cc/surfaces/surface_sequence.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+TEST(SurfaceSequenceGeneratorTest, Basic) {
+  SurfaceSequenceGenerator generator;
+  generator.set_surface_client_id(5);
+  SurfaceSequence sequence1 = generator.CreateSurfaceSequence();
+  SurfaceSequence sequence2 = generator.CreateSurfaceSequence();
+  EXPECT_NE(sequence1, sequence2);
+}
+
+}  // namespace
+}  // namespace cc