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

chrome/renderer/pepper/pepper_shared_memory_message_filter.cc

Index: chrome/renderer/pepper/pepper_shared_memory_message_filter.cc
===================================================================
--- chrome/renderer/pepper/pepper_shared_memory_message_filter.cc	(revision 270145)
+++ chrome/renderer/pepper/pepper_shared_memory_message_filter.cc	(working copy)
@@ -25,9 +25,9 @@
     const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PepperSharedMemoryMessageFilter, msg)
-  IPC_MESSAGE_HANDLER(PpapiHostMsg_SharedMemory_CreateSharedMemory,
-                      OnHostMsgCreateSharedMemory)
-  IPC_MESSAGE_UNHANDLED(handled = false)
+    IPC_MESSAGE_HANDLER(PpapiHostMsg_SharedMemory_CreateSharedMemory,
+                        OnHostMsgCreateSharedMemory)
+    IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }