Revert of Revert "Moved text decoding to the parser thread"

Source/core/fetch/TextResourceDecoder.h

-/*
-    Copyright (C) 1999 Lars Knoll (knoll@mpi-hd.mpg.de)
-    Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
-    Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
-
-    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.
-
-    This library is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Library General Public License for more details.
-
-    You should have received a copy of the GNU Library General Public License
-    along with this library; see the file COPYING.LIB.  If not, write to
-    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-    Boston, MA 02110-1301, USA.
-
-*/
-
-#ifndef TextResourceDecoder_h
-#define TextResourceDecoder_h
-
-#include "wtf/RefCounted.h"
-#include "wtf/text/TextEncoding.h"
-
-namespace WebCore {
-
-class HTMLMetaCharsetParser;
-
-class TextResourceDecoder {
-public:
-    enum EncodingSource {
-        DefaultEncoding,
-        AutoDetectedEncoding,
-        EncodingFromContentSniffing,
-        EncodingFromXMLHeader,
-        EncodingFromMetaTag,
-        EncodingFromCSSCharset,
-        EncodingFromHTTPHeader,
-        UserChosenEncoding,
-        EncodingFromParentFrame
-    };
-
-    static PassOwnPtr<TextResourceDecoder> create(const String& mimeType, const WTF::TextEncoding& defaultEncoding = WTF::TextEncoding(), bool usesEncodingDetector = false)
-    {
-        return adoptPtr(new TextResourceDecoder(mimeType, defaultEncoding, usesEncodingDetector));
-    }
-    ~TextResourceDecoder();
-
-    void setEncoding(const WTF::TextEncoding&, EncodingSource);
-    const WTF::TextEncoding& encoding() const { return m_encoding; }
-    bool encodingWasDetectedHeuristically() const
-    {
-        return m_source == AutoDetectedEncoding
-            || m_source == EncodingFromContentSniffing;
-    }
-
-    String decode(const char* data, size_t length);
-    String flush();
-
-    void setHintEncoding(const WTF::TextEncoding& encoding)
-    {
-        m_hintEncoding = encoding.name();
-    }
-
-    void useLenientXMLDecoding() { m_useLenientXMLDecoding = true; }
-    bool sawError() const { return m_sawError; }
-
-private:
-    TextResourceDecoder(const String& mimeType, const WTF::TextEncoding& defaultEncoding, bool usesEncodingDetector);
-
-    enum ContentType { PlainText, HTML, XML, CSS }; // PlainText only checks for BOM.
-    static ContentType determineContentType(const String& mimeType);
-    static const WTF::TextEncoding& defaultEncoding(ContentType, const WTF::TextEncoding& defaultEncoding);
-
-    size_t checkForBOM(const char*, size_t);
-    bool checkForCSSCharset(const char*, size_t, bool& movedDataToBuffer);
-    bool checkForXMLCharset(const char*, size_t, bool& movedDataToBuffer);
-    void checkForMetaCharset(const char*, size_t);
-    void detectJapaneseEncoding(const char*, size_t);
-    bool shouldAutoDetect() const;
-
-    ContentType m_contentType;
-    WTF::TextEncoding m_encoding;
-    OwnPtr<TextCodec> m_codec;
-    EncodingSource m_source;
-    const char* m_hintEncoding;
-    Vector<char> m_buffer;
-    bool m_checkedForBOM;
-    bool m_checkedForCSSCharset;
-    bool m_checkedForXMLCharset;
-    bool m_checkedForMetaCharset;
-    bool m_useLenientXMLDecoding; // Don't stop on XML decoding errors.
-    bool m_sawError;
-    bool m_usesEncodingDetector;
-
-    OwnPtr<HTMLMetaCharsetParser> m_charsetParser;
-};
-
-}
-
-#endif