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

ppapi/native_client/tests/ppapi_browser/ppb_instance/ppapi_ppb_instance.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 "native_client/src/shared/platform/nacl_check.h"
 #include "native_client/tests/ppapi_test_lib/get_browser_interface.h"
 #include "native_client/tests/ppapi_test_lib/test_interface.h"
 
 #include "ppapi/c/pp_size.h"
 #include "ppapi/c/ppb_image_data.h"
 #include "ppapi/c/ppb_instance.h"
@@ skipping 60 matching lines @@
 }  // namespace
 
 void SetupTests() {
   RegisterTest("TestIsFullFrame", TestIsFullFrame);
   RegisterTest("TestBindGraphics", TestBindGraphics);
 }
 
 void SetupPluginInterfaces() {
   // none
 }