Add support for passing an arbitrary parameter to an IPC message handler. The motivation is for Web…

ppapi/proxy/dispatch_reply_message.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.
 
 // This file provides infrastructure for dispatching messasges from host
 // resource, inlcuding reply messages or unsolicited replies. Normal IPC Reply
 // handlers can't take extra parameters. We want to take a
 // ResourceMessageReplyParams as a parameter.
 
 #ifndef PPAPI_PROXY_DISPATCH_REPLY_MESSAGE_H_
@@ skipping 111 matching lines @@
 void DispatchResourceReplyOrDefaultParams(
     base::Callback<void(const ResourceMessageReplyParams&)>* obj,
     Method method,
     const ResourceMessageReplyParams& reply_params,
     const IPC::Message& msg) {
   DCHECK(msg.type() == MsgClass::ID || msg.type() == 0)
       << "Resource reply message of unexpected type.";
   (obj->*method)(reply_params);
 }
 
+#define PPAPI_BEGIN_MESSAGE_MAP(class_name, msg) \
+  { \
+    typedef class_name _IpcMessageHandlerClass; \
+    const IPC::Message& ipc_message__ = msg; \
+    switch (ipc_message__.type()) { \
+
 // Note that this only works for message with 1 or more parameters. For
 // 0-parameter messages you need to use the _0 version below (since there are
 // no params in the message).
 #define PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(msg_class, member_func) \
     case msg_class::ID: { \
       msg_class::Schema::Param p; \
       if (msg_class::Read(&ipc_message__, &p)) { \
         ppapi::proxy::DispatchResourceReply( \
             this, \
             &_IpcMessageHandlerClass::member_func, \
             params, p); \
       } else { \
         NOTREACHED(); \
       } \
       break; \
     }
 
 #define PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL_0(msg_class, member_func) \
   case msg_class::ID: { \
     member_func(params); \
     break; \
   }
 
 #define PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL_UNHANDLED(code) \
     default: { \
         code; \
     } \
     break;
 
+#define PPAPI_END_MESSAGE_MAP() \
+  } \
+}
+
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_DISPATCH_REPLY_MESSAGE_H_