Move const PortName data out of header file

mojo/edk/system/core.cc

Index: mojo/edk/system/core.cc
diff --git a/mojo/edk/system/core.cc b/mojo/edk/system/core.cc
index f37d42ef3ec3fdd658a29b5511ee67ee3a576329..1c94489935a3afc0a0aa45879aa0b83e2a314e74 100644
--- a/mojo/edk/system/core.cc
+++ b/mojo/edk/system/core.cc
@@ -791,7 +791,7 @@ MojoResult Core::NotifyBadMessage(MojoMessageHandle message,
 
   const PortsMessage& ports_message =
       reinterpret_cast<MessageForTransit*>(message)->ports_message();
-  if (ports_message.source_node() == ports::kInvalidNodeName) {
+  if (ports_message.source_node() == ports::constants::kInvalidNodeName) {
     DVLOG(1) << "Received invalid message from unknown node.";
     if (!default_process_error_callback_.is_null())
       default_process_error_callback_.Run(std::string(error, error_num_bytes));