Add an IPC channel between the NaCl loader process and the renderer.

chrome/common/nacl_messages.h

Index: chrome/common/nacl_messages.h
===================================================================
--- chrome/common/nacl_messages.h	(revision 143509)
+++ chrome/common/nacl_messages.h	(working copy)
@@ -7,6 +7,7 @@
 // Multiply-included message file, no traditional include guard.
 #include "base/process.h"
 #include "chrome/common/nacl_types.h"
+#include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_macros.h"
 
 #define IPC_MESSAGE_START NaClMsgStart
@@ -18,6 +19,7 @@
   IPC_STRUCT_TRAITS_MEMBER(version)
   IPC_STRUCT_TRAITS_MEMBER(enable_exception_handling)
   IPC_STRUCT_TRAITS_MEMBER(enable_debug_stub)
+  IPC_STRUCT_TRAITS_MEMBER(enable_ipc_proxy)
 IPC_STRUCT_TRAITS_END()
 
 //-----------------------------------------------------------------------------
@@ -72,3 +74,9 @@
 // database in the browser.
 IPC_MESSAGE_CONTROL1(NaClProcessMsg_SetKnownToValidate,
                      std::string /* A validation signature */)
+
+// Notify the browser process that the server side of the PPAPI channel was
+// created successfully.
+IPC_MESSAGE_CONTROL1(NaClProcessHostMsg_PpapiChannelCreated,
+                     IPC::ChannelHandle /* channel_handle */)
+