Revert of UTF-8 detector for pages missing encoding info

third_party/WebKit/Source/core/xmlhttprequest/XMLHttpRequest.cpp

 /*
  *  Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
  *  Copyright (C) 2005-2007 Alexey Proskuryakov <ap@webkit.org>
  *  Copyright (C) 2007, 2008 Julien Chaffraix <jchaffraix@webkit.org>
  *  Copyright (C) 2008, 2011 Google Inc. All rights reserved.
  *  Copyright (C) 2012 Intel Corporation
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
@@ skipping 1526 matching lines @@
         m_responseDocumentParser->setDecoder(createDecoder());
 
     m_responseDocumentParser->appendBytes(data, len);
 }
 
 PassOwnPtr<TextResourceDecoder> XMLHttpRequest::createDecoder() const
 {
     if (m_responseTypeCode == ResponseTypeJSON)
         return TextResourceDecoder::create("application/json", "UTF-8");
 
-    if (!m_finalResponseCharset.isEmpty()) {
-        OwnPtr<TextResourceDecoder> decoder(TextResourceDecoder::create("text/plain"));
-        decoder->setEncoding(WTF::TextEncoding(m_finalResponseCharset), TextResourceDecoder::EncodingFromHTTPHeader);
-        return decoder.release();
-    }
+    if (!m_finalResponseCharset.isEmpty())
+        return TextResourceDecoder::create("text/plain", m_finalResponseCharset);
 
     // allow TextResourceDecoder to look inside the m_response if it's XML or HTML
     if (responseIsXML()) {
         OwnPtr<TextResourceDecoder> decoder = TextResourceDecoder::create("application/xml");
         // Don't stop on encoding errors, unlike it is done for other kinds
         // of XML resources. This matches the behavior of previous WebKit
         // versions, Firefox and Opera.
         decoder->useLenientXMLDecoding();
 
         return decoder.release();
@@ skipping 144 matching lines @@
     visitor->trace(m_responseDocumentParser);
     visitor->trace(m_progressEventThrottle);
     visitor->trace(m_upload);
     visitor->trace(m_blobLoader);
     XMLHttpRequestEventTarget::trace(visitor);
     DocumentParserClient::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink