mandoline: Add automatic tracing at mojo call sites.

content/common/service_port_service.mojom

 // Copyright 2015 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.
 
 module content;
 
 enum ServicePortConnectResult {
   ACCEPT,
   REJECT
 };
 
 struct MojoTransferredMessagePort {
   int32 id;
   bool send_messages_as_values;
 };
 
 interface ServicePortService {
   SetClient(ServicePortServiceClient client);
 
   Connect(string target_url, string origin)
       => (ServicePortConnectResult result, int32 port_id);
 
-  PostMessage(int32 port_id, string message,
-              array<MojoTransferredMessagePort> ports);
+  PostMessageToPort(int32 port_id, string message,
+                    array<MojoTransferredMessagePort> ports);
   ClosePort(int32 port_id);
 };
 
 interface ServicePortServiceClient {
-  PostMessage(int32 port_id, string message,
-              array<MojoTransferredMessagePort> ports,
-              array<int32> new_routing_ids);
+  PostMessageToPort(int32 port_id, string message,
+                    array<MojoTransferredMessagePort> ports,
+                    array<int32> new_routing_ids);
 };
 
 interface ServicePortDispatcher {
   Connect(string target_url, string origin, int32 port_id)
       => (ServicePortConnectResult result, string name, string data);
 };