Preserve custom headers when following cross-origin redirects.

third_party/WebKit/Source/core/loader/DocumentThreadableLoader.h

 /*
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 201 matching lines @@
 
   // Holds the original request for fallback in case the Service Worker
   // does not respond.
   ResourceRequest m_fallbackRequestForServiceWorker;
 
   // Holds the original request and options for it during preflight request
   // handling phase.
   ResourceRequest m_actualRequest;
   ResourceLoaderOptions m_actualOptions;
 
-  // stores simple request headers in case of a cross-origin redirect.
-  HTTPHeaderMap m_simpleRequestHeaders;
+  // stores request headers in case of a cross-origin redirect.
+  HTTPHeaderMap m_requestHeaders;
 
   Timer<DocumentThreadableLoader> m_timeoutTimer;
   double
       m_requestStartedSeconds;  // Time an asynchronous fetch request is started
 
   // Max number of times that this DocumentThreadableLoader can follow
   // cross-origin redirects. This is used to limit the number of redirects. But
   // this value is not the max number of total redirects allowed, because
   // same-origin redirects are not counted here.
   int m_corsRedirectLimit;
 
   WebURLRequest::FetchRedirectMode m_redirectMode;
 
   // Holds the referrer after a redirect response was received. This referrer is
   // used to populate the HTTP Referer header when following the redirect.
   bool m_overrideReferrer;
   Referrer m_referrerAfterRedirect;
 
   RawResourceClientStateChecker m_checker;
 };
 
 }  // namespace blink
 
 #endif  // DocumentThreadableLoader_h