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

ppapi/native_client/tests/ppapi_browser/progress_events/ppapi_progress_events.js

-// 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.
 
 // Class to track the progress events received by a particular plugin instance.
 function EventStateMachine() {
   // Work around how JS binds 'this'.
   var this_ = this;
   // Given a particular state, what are the acceptable event types.
   this.expectedNext = {
     'BEGIN': { 'loadstart': 1 },
@@ skipping 128 matching lines @@
   tester.addTest('last_error_string_' + embedId, function() {
     // If an error or abort was reported, check that lastError is set
     // to the correct value.
     if ((eventMachine.stateHistogram['error'] > 0 ||
          eventMachine.stateHistogram['abort'] > 0)) {
       var embed = $(embedId);
       assertEqual(embed.lastError, lastError);
     }
   });
 }