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

content/common/cc_messages.h

Index: content/common/cc_messages.h
diff --git a/content/common/cc_messages.h b/content/common/cc_messages.h
index fb3bf98dd164c1d1024cf3c5d1de3510431a918c..25f874294ac8f4d16eb08b717dd8c8106296f70f 100644
--- a/content/common/cc_messages.h
+++ b/content/common/cc_messages.h
@@ -21,6 +21,7 @@
 #include "cc/video_layer_impl.h"
 #include "cc/yuv_video_draw_quad.h"
 #include "content/common/content_export.h"
+#include "gpu/ipc/gpu_command_buffer_traits.h"
 #include "ipc/ipc_message_macros.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebFilterOperation.h"
 
@@ -75,14 +76,6 @@ struct CONTENT_EXPORT ParamTraits<cc::RenderPass> {
 };
 
 template<>
-struct CONTENT_EXPORT ParamTraits<cc::Mailbox> {
-  typedef cc::Mailbox 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);
-};
-
-template<>
 struct CONTENT_EXPORT ParamTraits<cc::CompositorFrame> {
   typedef cc::CompositorFrame param_type;
   static void Write(Message* m, const param_type& p);