Change NaCl IPC PPAPI proxy startup to support a NaCl-Browser process

ppapi/proxy/ppapi_messages.h

Index: ppapi/proxy/ppapi_messages.h
===================================================================
--- ppapi/proxy/ppapi_messages.h	(revision 154143)
+++ ppapi/proxy/ppapi_messages.h	(working copy)
@@ -266,6 +266,14 @@
                      int /* renderer_id */,
                      bool /* incognito */)
 
+// Creates a channel to talk to a renderer. This message is only used by the
+// NaCl IPC proxy. It is intercepted by NaClIPCAdapter, which creates the
+// actual channel and rewrites the message for the untrusted side.
+IPC_MESSAGE_CONTROL3(PpapiMsg_CreateNaClChannel,
+                     int /* renderer_id */,
+                     bool /* incognito */,
+                     ppapi::proxy::SerializedHandle /* channel_handle */)
+
 // Each plugin may be referenced by multiple renderers. We need the instance
 // IDs to be unique within a plugin, despite coming from different renderers,
 // and unique within a renderer, despite going to different plugins. This means