Reviewed by Eric.

    Reviewed by Eric.

        - http://bugzilla.opendarwin.org/show_bug.cgi?id=5620
        Should only honor encoding from <meta> in HTML

        - http://bugzilla.opendarwin.org/show_bug.cgi?id=9783
        An XML declaration without an explicit encoding incorrectly triggers
        UTF-8 encoding in an HTML document

        - http://bugzilla.opendarwin.org/show_bug.cgi?id=10155
        CSS2: @charset is not supported

WebCore:
        * loader/Decoder.cpp:
        (Decoder::Decoder): Decoder now knows what kind of content it is decoding.
        Also, the browser default encoding can now be passed directly to the constructor,
        to streamline the logic.
        (Decoder::decode): Add support for @charset, differentiate between HTML and XML.
        (Decoder::setEncodingName): Style cleanup.
        (Decoder::encodingName): Ditto.
        (Decoder::flush): Ditto.
        * loader/Decoder.h:
        (WebCore::Decoder::):

        * bridge/mac/WebCoreEncodings.mm: Pass a content type of text/html to Decoder.

        * loader/CachedCSSStyleSheet.cpp:
        (WebCore::CachedCSSStyleSheet::CachedCSSStyleSheet):
        (WebCore::CachedCSSStyleSheet::setCharset):
        (WebCore::CachedCSSStyleSheet::data):
        * loader/CachedCSSStyleSheet.h:
        Use Decoder instead of TextEncoding::toUnicode() to enable @charset support.

        * loader/CachedXBLDocument.cpp:
        (WebCore::CachedXBLDocument::CachedXBLDocument): Pass a content type.
        * loader/CachedXSLStyleSheet.cpp:
        (WebCore::CachedXSLStyleSheet::CachedXSLStyleSheet): Ditto.
        (WebCore::CachedXSLStyleSheet::data): Flush the decoder to be safe.

        * page/Frame.cpp:
        (WebCore::Frame::write): Pass a content type and a default encoding to
        the Decoder.
        * xml/XSLTProcessor.cpp:
        (WebCore::XSLTProcessor::createDocumentFromSource): Pass the output document
        MIME type.
        * xml/xmlhttprequest.cpp:
        (WebCore::XMLHttpRequest::receivedData): Ditto.

LayoutTests:
        * fast/encoding/css-charset-expected.txt: Added.
        * fast/encoding/css-charset.css: Added.
        * fast/encoding/css-charset.html: Added.
        * fast/encoding/css-charset-evil-expected.txt: Added.
        * fast/encoding/css-charset-evil.css: Added.
        * fast/encoding/css-charset-evil.html: Added.
        * fast/encoding/default-xhtml-encoding-expected.txt: Added.
        * fast/encoding/default-xhtml-encoding.xhtml: Added.
        * fast/encoding/meta-in-xhtml-expected.txt: Added.
        * fast/encoding/meta-in-xhtml.xhtml: Added.
        * fast/encoding/pseudo-xml-2-expected.txt: Added.
        * fast/encoding/pseudo-xml-2.html: Added.
        * fast/encoding/pseudo-xml-3-expected.txt: Added.
        * fast/encoding/pseudo-xml-3.html: Added.
        * fast/encoding/pseudo-xml-4-expected.txt: Added.
        * fast/encoding/pseudo-xml-4.html: Added.
        * fast/encoding/pseudo-xml-expected.txt: Added.
        * fast/encoding/pseudo-xml.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@16175 268f45cc-cd09-0410-ab3c-d52691b4dbfc