Remove unused prefs/api/resource for setPageEncoding

third_party/WebKit/Source/core/html/parser/TextResourceDecoder.cpp

 /*
     Copyright (C) 1999 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
     Copyright (C) 2005, 2006, 2007 Alexey Proskuryakov (ap@nypop.com)
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
@@ skipping 119 matching lines @@
 TextResourceDecoder::~TextResourceDecoder()
 {
 }
 
 void TextResourceDecoder::setEncoding(const WTF::TextEncoding& encoding, EncodingSource source)
 {
     // In case the encoding didn't exist, we keep the old one (helps some sites specifying invalid encodings).
     if (!encoding.isValid())
         return;
 
+    // Default encoding for XML content should remain as UTF-8 even if the autodetection comes into play

[Jinsuk Kim, 2016/09/05 10:08:50]

This change was made to make following XML tests pass:

fast/encoding/default-xhtml-encoding.xhtml 
fast/encoding/meta-in-xhtml.xhtml
dom/xhtml/level3/core/documentgetinputencoding01.xhtml

[tkent, 2016/09/05 23:53:45]

Why did they fail?  Did the other part of this CL change an XML behavior?

+    // to detect it as Latin-1.
+    if (m_contentType == XMLContent && source == EncodingFromContentSniffing && encoding == Latin1Encoding())
+        return;
+
     // When encoding comes from meta tag (i.e. it cannot be XML files sent via XHR),
-    // treat x-user-defined as windows-1252 (bug 18270)
+    // treat x-user-defined as windows-1252 (bug 18270).
     if (source == EncodingFromMetaTag && !strcasecmp(encoding.name(), "x-user-defined"))
         m_encoding = "windows-1252";
     else if (source == EncodingFromMetaTag || source == EncodingFromXMLHeader || source == EncodingFromCSSCharset)
         m_encoding = encoding.closestByteBasedEquivalent();
     else
         m_encoding = encoding;
 
     m_codec.reset();
     m_source = source;
 }
@@ skipping 292 matching lines @@
         m_codec = newTextCodec(m_encoding);
 
     String result = m_codec->decode(m_buffer.data(), m_buffer.size(), FetchEOF, m_contentType == XMLContent && !m_useLenientXMLDecoding, m_sawError);
     m_buffer.clear();
     m_codec.reset();
     m_checkedForBOM = false; // Skip BOM again when re-decoding.
     return result;
 }
 
 } // namespace blink