cc: Add SwapPromiseManager and SurfaceSequenceGenerator.

cc/trees/surface_sequence_generator.h

Index: cc/trees/surface_sequence_generator.h
diff --git a/cc/trees/surface_sequence_generator.h b/cc/trees/surface_sequence_generator.h
new file mode 100644
index 0000000000000000000000000000000000000000..10b880ad5fb84d3ac2143b1e54a60abe1aa8446f
--- /dev/null
+++ b/cc/trees/surface_sequence_generator.h
@@ -0,0 +1,37 @@
+// 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.
+
+#ifndef CC_TREES_SURFACE_SEQUENCE_GENERATOR_H_
+#define CC_TREES_SURFACE_SEQUENCE_GENERATOR_H_
+
+#include <stdint.h>
+
+#include "base/macros.h"
+#include "cc/base/cc_export.h"
+
+namespace cc {
+struct SurfaceSequence;
+
+// Generates unique surface sequences for a surface client id.
+class CC_EXPORT SurfaceSequenceGenerator {
+ public:
+  SurfaceSequenceGenerator();
+  ~SurfaceSequenceGenerator();
+
+  void set_surface_client_id(uint32_t client_id) {
+    surface_client_id_ = client_id;
+  }
+
+  SurfaceSequence CreateSurfaceSequence();
+
+ private:
+  uint32_t surface_client_id_;
+  uint32_t next_surface_sequence_;
+
+  DISALLOW_COPY_AND_ASSIGN(SurfaceSequenceGenerator);
+};
+
+}  // namespace cc
+
+#endif  // CC_TREES_SURFACE_SEQUENCE_GENERATOR_H_