WIP: Propagate SurfaceID up window tree hierarchy

cc/ipc/frame_sink_id_struct_traits.h

+// 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_IPC_FRAME_SINK_ID_STRUCT_TRAITS_H_
+#define CC_IPC_FRAME_SINK_ID_STRUCT_TRAITS_H_
+
+#include "cc/ipc/frame_sink_id.mojom-shared.h"
+#include "cc/surfaces/frame_sink_id.h"
+
+namespace mojo {
+
+template <>
+struct StructTraits<cc::mojom::FrameSinkIdDataView, cc::FrameSinkId> {
+  static uint32_t client_id(const cc::FrameSinkId& frame_sink_id) {
+    return frame_sink_id.client_id();
+  }
+
+  static uint32_t sink_id(const cc::FrameSinkId& frame_sink_id) {
+    return frame_sink_id.sink_id();
+  }
+
+  static bool Read(cc::mojom::FrameSinkIdDataView data, cc::FrameSinkId* out) {
+    *out = cc::FrameSinkId(data.client_id(), data.sink_id());
+    return true;
+  }
+};
+
+}  // namespace mojo
+
+#endif  // CC_IPC_FRAME_SINK_ID_STRUCT_TRAITS_H_