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

ppapi/native_client/tests/ppapi_simple_tests/event.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 <stdint.h>
 #include <stdlib.h>
 
 #include <sstream>
 #include <string>
 #include <queue>
 
@@ skipping 229 matching lines @@
   virtual pp::Instance* CreateInstance(PP_Instance instance) {
     return new MyInstance(instance);
   }
 };
 
 namespace pp {
   Module* CreateModule() {
     return new MyModule();
   }
 }