Update HTTPHeaderMap wrappers to use AtomicString type for header values

Source/core/fetch/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 23 matching lines @@
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
 
 bool isOnAccessControlSimpleRequestMethodWhitelist(const String& method)
 {
     return method == "GET" || method == "HEAD" || method == "POST";
 }
 
-bool isOnAccessControlSimpleRequestHeaderWhitelist(const String& name, const String& value)
+bool isOnAccessControlSimpleRequestHeaderWhitelist(const AtomicString& name, const AtomicString& value)
 {
     if (equalIgnoringCase(name, "accept")
         || equalIgnoringCase(name, "accept-language")
         || equalIgnoringCase(name, "content-language")
         || 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);
+        AtomicString mimeType = extractMIMETypeFromMediaType(value);
         return equalIgnoringCase(mimeType, "application/x-www-form-urlencoded")
             || equalIgnoringCase(mimeType, "multipart/form-data")
             || equalIgnoringCase(mimeType, "text/plain");
     }
 
     return false;
 }
 
 bool isSimpleCrossOriginAccessRequest(const String& method, const HTTPHeaderMap& headerMap)
 {
@@ skipping 121 matching lines @@
     Vector<String> headers;
     headerValue.split(',', false, headers);
     for (unsigned headerCount = 0; headerCount < headers.size(); headerCount++) {
         String strippedHeader = headers[headerCount].stripWhiteSpace();
         if (!strippedHeader.isEmpty())
             headerSet.add(strippedHeader);
     }
 }
 
 } // namespace WebCore