Move Mailbox from cc to gpu, and its traits to gpu/ipc

gpu/command_buffer/common/mailbox.h

Index: gpu/command_buffer/common/mailbox.h
diff --git a/gpu/command_buffer/common/mailbox.h b/gpu/command_buffer/common/mailbox.h
new file mode 100644
index 0000000000000000000000000000000000000000..c0ae06f80d4eebd4dd18768689311788ea321cd5
--- /dev/null
+++ b/gpu/command_buffer/common/mailbox.h
@@ -0,0 +1,23 @@
+// Copyright 2013 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 GPU_COMMAND_BUFFER_MAILBOX_H_
+#define GPU_COMMAND_BUFFER_MAILBOX_H_
+
+#include "../../gpu_export.h"
+#include "../common/types.h"
+
+namespace gpu {
+
+struct GPU_EXPORT Mailbox {
+  Mailbox();
+  bool IsZero() const;
+  void SetName(const int8* name);
+  int8 name[64];
+};
+
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_MAILBOX_H_
+