Merge 93188 - REGRESSION (r89086): All worker xhr requests trigger preflight requests.

Source/WebCore/loader/CrossOriginAccessControl.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 28 matching lines @@
 bool isOnAccessControlSimpleRequestMethodWhitelist(const String& method)
 {
     return method == "GET" || method == "HEAD" || method == "POST";
 }
 
 bool isOnAccessControlSimpleRequestHeaderWhitelist(const String& name, const String& value)
 {
     if (equalIgnoringCase(name, "accept")
         || equalIgnoringCase(name, "accept-language")
         || equalIgnoringCase(name, "content-language")
-        || equalIgnoringCase(name, "origin"))
+        || equalIgnoringCase(name, "origin")
+        || equalIgnoringCase(name, "referer"))
         return true;
 
     // Preflight is required for MIME types that can not be sent via form submission.
     if (equalIgnoringCase(name, "content-type")) {
         String mimeType = extractMIMETypeFromMediaType(value);
         return equalIgnoringCase(mimeType, "application/x-www-form-urlencoded")
             || equalIgnoringCase(mimeType, "multipart/form-data")
             || equalIgnoringCase(mimeType, "text/plain");
     }
 
@@ skipping 100 matching lines @@
         if (accessControlCredentialsString != "true") {
             errorDescription = "Credentials flag is true, but Access-Control-Allow-Credentials is not \"true\".";
             return false;
         }
     }
 
     return true;
 }
 
 } // namespace WebCore