Update comments referring to Chromium-side src/trusted/plugin code

src/trusted/service_runtime/env_cleanser.c

 /*
  * Copyright (c) 2011 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ skipping 30 matching lines @@
   "LC_IDENTIFICATION",
   "LC_MEASUREMENT",
   "LC_MESSAGES",
   "LC_MONETARY",
   "LC_NAME",
   "LC_NUMERIC",
   "LC_PAPER",
   "LC_TELEPHONE",
   "LC_TIME",
   "NACLVERBOSITY",
-  "NACL_PLUGIN_DEBUG",      /* src/trusted/plugin/srpc/utility.cc */
+  "NACL_PLUGIN_DEBUG",      /* Chromium's plugin/utility.cc */
   "NACL_SRPC_DEBUG",        /* src/shared/srpc/utility.c */
   NULL,
 };
 
 /* left arg is key, right arg is table entry */
 static int EnvCmp(void const *vleft, void const *vright) {
   char const *left = *(char const *const *) vleft;
   char const *right = *(char const *const *) vright;
   char cleft, cright;
 
@@ skipping 110 matching lines @@
 }
 
 char const *const *NaClEnvCleanserEnvironment(struct NaClEnvCleanser *self) {
   return (char const *const *) self->cleansed_environ;
 }
 
 void NaClEnvCleanserDtor(struct NaClEnvCleanser *self) {
   free((void *) self->cleansed_environ);
   self->cleansed_environ = NULL;
 }