Support using a Mojo message pipe in a ChannelHandle.

ipc/ipc_mojo_param_traits.h

Index: ipc/ipc_mojo_param_traits.h
diff --git a/ipc/ipc_mojo_param_traits.h b/ipc/ipc_mojo_param_traits.h
index a474f7b1df9a9dbb5ef5882a47d96aae1e9f7dd8..39be43e217a300d337f0cd7d9e9fcb96041ae54f 100644
--- a/ipc/ipc_mojo_param_traits.h
+++ b/ipc/ipc_mojo_param_traits.h
@@ -12,18 +12,20 @@
 #include "mojo/public/cpp/system/message_pipe.h"
 
 namespace base {
+class Pickle;
 class PickleIterator;
+class PickleSizer;
 }
 
 namespace IPC {
 
-class Message;
-
 template <>
 struct IPC_EXPORT ParamTraits<mojo::MessagePipeHandle> {
   typedef mojo::MessagePipeHandle param_type;
-  static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, base::PickleIterator* iter, param_type* r);
+  static void GetSize(base::PickleSizer* sizer, const param_type& p);
+  static void Write(base::Pickle* m, const param_type& p);
+  static bool Read(const base::Pickle* m, base::PickleIterator* iter,
+                   param_type* r);
   static void Log(const param_type& p, std::string* l);
 };