When launching PNaCl helper nexes, explicitly disable IRT loading.

chrome/renderer/pepper/ppb_nacl_private_impl.cc

Index: chrome/renderer/pepper/ppb_nacl_private_impl.cc
diff --git a/chrome/renderer/pepper/ppb_nacl_private_impl.cc b/chrome/renderer/pepper/ppb_nacl_private_impl.cc
index bb5abf6ee04332a94a9826a714f9ac6cfff66165..79f5518673405122976f3bfed6666540fcef6be7 100644
--- a/chrome/renderer/pepper/ppb_nacl_private_impl.cc
+++ b/chrome/renderer/pepper/ppb_nacl_private_impl.cc
@@ -67,6 +67,7 @@ static int GetRoutingID(PP_Instance instance) {
 // Launch NaCl's sel_ldr process.
 PP_NaClResult LaunchSelLdr(PP_Instance instance,
                            const char* alleged_url,
+                           PP_Bool uses_irt,
                            PP_Bool uses_ppapi,
                            PP_Bool enable_ppapi_dev,
                            int socket_count,
@@ -103,7 +104,9 @@ PP_NaClResult LaunchSelLdr(PP_Instance instance,
           instance_info.url,
           routing_id,
           perm_bits,
-          socket_count, &sockets,
+          PP_ToBool(uses_irt),
+          socket_count,
+          &sockets,
           &instance_info.channel_handle,
           &instance_info.plugin_child_id))) {
     return PP_NACL_FAILED;