some situations.

        * WebCoreSupport.subproj/WebTextRenderer.m:
        (-[WebTextRenderer _floatWidthForCharacters:stringLength:fromCharacterPosition:numberOfCharacters:withPadding:applyRounding:attemptFontSubstitution:widths:fonts:glyphs:numGlyphs:letterSpacing:wordSpacing:]):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@2645 268f45cc-cd09-0410-ab3c-d52691b4dbfc