Fix typo in untrusted/irt_stub/BUILD.gn

ppapi/native_client/src/untrusted/irt_stub/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 assert(is_nacl,
        "These targets must only be built using the untrusted NaCl toolchains.")
 
-# TODO(sbc): Make sure this library gets built with -fPIC.  Right not it
+# TODO(sbc): Make sure this library gets built with -fPIC.  Right now it
 # doesn't seem that is built at all.
 source_set("ppapi_stub_lib") {
   sources = [
     "plugin_main_irt.c",
     "ppapi_plugin_main.c",
     "ppapi_plugin_start.c",
     "thread_creator.c",
   ]
 }