PNaCl: Use Chrome IPC to talk to the linker process, instead of SRPC

ppapi/proxy/ppapi_messages.h

Index: ppapi/proxy/ppapi_messages.h
diff --git a/ppapi/proxy/ppapi_messages.h b/ppapi/proxy/ppapi_messages.h
index 3bc0d5fe694fe275c3f1911f8070010850c7b8fd..dcde9d9dca9aaea37838d62b955cf5dc18c3621f 100644
--- a/ppapi/proxy/ppapi_messages.h
+++ b/ppapi/proxy/ppapi_messages.h
@@ -868,6 +868,18 @@ IPC_SYNC_MESSAGE_ROUTED1_1(PpapiMsg_PPPInstancePrivate_GetInstanceObject,
 
 #endif  // !defined(OS_NACL) && !defined(NACL_WIN64)
 
+// Calls the PNaCl linker process to link the given object files together
+// to produce a nexe file.  Note that this PNaCl translation plumbing is
+// not part of PPAPI proper, but this message is defined here because it
+// needs to use the ppapi::proxy::SerializedHandle type.
+IPC_SYNC_MESSAGE_CONTROL2_1(PpapiMsg_PnaclTranslatorLink,
+                            /* object file FDs for inputs */
+                            std::vector<ppapi::proxy::SerializedHandle>,
+                            /* nexe file FD for output */
+                            ppapi::proxy::SerializedHandle,
+                            /* success status result */
+                            bool)
+
 // Reports to the browser that a plugin has been active.
 IPC_MESSAGE_CONTROL0(PpapiHostMsg_Keepalive)
 
@@ -885,6 +897,9 @@ IPC_MESSAGE_CONTROL1(PpapiHostMsg_ChannelCreated,
 IPC_MESSAGE_CONTROL0(PpapiHostMsg_StartupInitializationComplete)
 
 // Calls renderer to open a resource file for nacl_irt_open_resource().
+// Note that open_resource() is not part of PPAPI proper, but this message
+// is defined here because it needs to use the
+// ppapi::proxy::SerializedHandle type.
 IPC_SYNC_MESSAGE_CONTROL1_3(PpapiHostMsg_OpenResource,
                             std::string /* key */,
                             ppapi::proxy::SerializedHandle /* fd */,