Add mouse input forwarding to gpu service

gpu/ipc/gpu_command_buffer_traits.h

Index: gpu/ipc/gpu_command_buffer_traits.h
diff --git a/gpu/ipc/gpu_command_buffer_traits.h b/gpu/ipc/gpu_command_buffer_traits.h
index 345163948d3b1709db2fad974cf833bc892042f5..1c7e02e76e532bca8f47ae85f78d719d8522a279 100644
--- a/gpu/ipc/gpu_command_buffer_traits.h
+++ b/gpu/ipc/gpu_command_buffer_traits.h
@@ -13,6 +13,7 @@
 namespace gpu {
 struct Mailbox;
 struct MailboxHolder;
+union ValueState;
 }
 
 namespace IPC {
@@ -41,6 +42,14 @@ struct GPU_EXPORT ParamTraits<gpu::MailboxHolder> {
   static void Log(const param_type& p, std::string* l);
 };
 
+template <>
+struct GPU_EXPORT ParamTraits<gpu::ValueState> {
+  typedef gpu::ValueState param_type;
+  static void Write(Message* m, const param_type& p);
+  static bool Read(const Message* m, PickleIterator* iter, param_type* p);
+  static void Log(const param_type& p, std::string* l);
+};
+
 }  // namespace IPC
 
 #endif  // GPU_IPC_GPU_PARAM_TRAITS_H_