Simplify IPC::SyncMessageSchema::WriteReplyParams() using variadic templates

ipc/ipc_message_utils.h

 // Copyright (c) 2012 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.
 
 #ifndef IPC_IPC_MESSAGE_UTILS_H_
 #define IPC_IPC_MESSAGE_UTILS_H_
 
 #include <algorithm>
 #include <map>
 #include <set>
@@ skipping 888 matching lines @@
       ConnectMessageAndReply(msg, reply);
       DispatchToMethod(obj, func, send_params, &t);
     } else {
       NOTREACHED() << "Error deserializing message " << msg->type();
       reply->set_reply_error();
       obj->Send(reply);
     }
     return ok;
   }
 
-  template<typename TA>
-  static void WriteReplyParams(Message* reply, TA a) {
-    ReplyParam p(a);
-    WriteParam(reply, p);
-  }
-
-  template<typename TA, typename TB>
-  static void WriteReplyParams(Message* reply, TA a, TB b) {
-    ReplyParam p(a, b);
-    WriteParam(reply, p);
-  }
-
-  template<typename TA, typename TB, typename TC>
-  static void WriteReplyParams(Message* reply, TA a, TB b, TC c) {
-    ReplyParam p(a, b, c);
-    WriteParam(reply, p);
-  }
-
-  template<typename TA, typename TB, typename TC, typename TD>
-  static void WriteReplyParams(Message* reply, TA a, TB b, TC c, TD d) {
-    ReplyParam p(a, b, c, d);
-    WriteParam(reply, p);
-  }
-
-  template<typename TA, typename TB, typename TC, typename TD, typename TE>
-  static void WriteReplyParams(Message* reply, TA a, TB b, TC c, TD d, TE e) {
-    ReplyParam p(a, b, c, d, e);
+  template<typename... T>

[Tom Sepez, 2015/03/25 17:11:58]

Nit: space before < (not your fault, but lets fix it).
Nit: generally we use Ts instead of T for variadic templates (as in "plural of
T"
Nit: prefer "args" to "a", again since it sounds plural.

+  static void WriteReplyParams(Message* reply, T... a) {
+    ReplyParam p(a...);
     WriteParam(reply, p);
   }
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_MESSAGE_UTILS_H_