Update Native Client Authors to be Chromium Authors for the code moved from the

ppapi/native_client/tests/ppapi_browser/ppb_var/ppapi_ppb_var.cc

-// Copyright (c) 2011 The Native Client Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
 #include <pthread.h>
 #include <stdio.h>
 #include <string.h>
 #include <new>
 #include <vector>
 
 #include "native_client/src/include/nacl_scoped_ptr.h"
@@ skipping 97 matching lines @@
 void SetupTests() {
   var_interface = PPBVar();
   EXPECT(var_interface != NULL);
   RegisterTest("TestStringVarCreateDelete", TestStringVarCreateDelete);
   RegisterTest("TestStringVarRefCount", TestStringVarRefCount);
 }
 
 void SetupPluginInterfaces() {
   // none
 }