Reviewed by Simon Fraser, Dan Bernstein.

        Speed up the PLT by devirtualizing the height() function on InlineBox.  virtualizing it in order to make the height() computation dynamic caused
        a ~0.5% slowdown.  This patch does the following to get the speed back:
        
        (a) Devirtualizes isText and forces inline box creators to set the bit as needed.  This actually resulted in simplified code, since ListMarkerBox could
        then be removed.
        (b) Reduces the height() call count.  In some cases the code was repeatedly calling height(), which used to be fine when the function was just an inline
        member variable access.  The call sites have been patched to cut down on extra height() calls now that it is more expensive.
        (c) Devirtualize height() except on SVG boxes.  For all non-SVG, the height() function on InlineBox handles the computation.  For SVG boxes, a new bit has
        been set on InlineBoxes (isSVG()) that indicates that the virtual svgBoxHeight() function should be called to retrieve the height instead.

        * GNUmakefile.am:
        * WebCore.pro:
        * WebCore.vcproj/WebCore.vcproj:
        * WebCore.xcodeproj/project.pbxproj:
        * WebCoreSources.bkl:
        * rendering/InlineBox.cpp:
        (WebCore::InlineBox::height):
        * rendering/InlineBox.h:
        (WebCore::InlineBox::InlineBox):
        (WebCore::InlineBox::isSVG):
        (WebCore::InlineBox::setIsSVG):
        (WebCore::InlineBox::isText):
        (WebCore::InlineBox::setIsText):
        (WebCore::InlineBox::svgBoxHeight):
        * rendering/InlineFlowBox.cpp:
        (WebCore::InlineFlowBox::placeBoxesVertically):
        (WebCore::InlineFlowBox::paintBoxDecorations):
        (WebCore::InlineFlowBox::paintMask):
        * rendering/InlineFlowBox.h:
        * rendering/InlineTextBox.cpp:
        * rendering/InlineTextBox.h:
        * rendering/ListMarkerBox.cpp: Removed.
        * rendering/ListMarkerBox.h: Removed.
        * rendering/RenderListMarker.cpp:
        (WebCore::RenderListMarker::createInlineBox):
        * rendering/RenderSVGInline.cpp:
        (WebCore::RenderSVGInline::createFlowBox):
        * rendering/RenderSVGInlineText.cpp:
        (WebCore::RenderSVGInlineText::createTextBox):
        * rendering/RenderSVGText.cpp:
        (WebCore::RenderSVGText::createRootBox):
        * rendering/RenderText.cpp:
        (WebCore::RenderText::createInlineTextBox):
        * rendering/RootInlineBox.cpp:
        * rendering/RootInlineBox.h:
        * rendering/SVGInlineFlowBox.h:
        (WebCore::SVGInlineFlowBox::svgBoxHeight):
        * rendering/SVGInlineTextBox.h:
        (WebCore::SVGInlineTextBox::svgBoxHeight):
        * rendering/SVGRootInlineBox.h:
        (WebCore::SVGRootInlineBox::svgBoxHeight):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@42846 268f45cc-cd09-0410-ab3c-d52691b4dbfc