Part of Bug 17221: Node highlight should show node metrics

        <http://bugs.webkit.org/show_bug.cgi?id=17221>
        <rdar://problem/5732822>

        Outstanding issues:
          1) We don't show padding/border/margins for inlines
          2) We don't show any numeric metrics, we just draw the boxes
          3) We'll probably want to tweak the look of the highlight some, at
             least to make the boxes better distinguishable

        Reviewed by Tim Hatcher.

        * page/InspectorController.cpp:
        (WebCore::drawOutlinedRect): Added. Just draws a single rect.
        (WebCore::drawHighlightForBoxes): Added. Takes the rects we calculated
        for the node and draws the highlight.
        (WebCore::InspectorController::drawNodeHighlight): Calculates the
        content/padding/border/margin boxes for blocks and passes them off to
        drawHighlightForBoxes. The behavior for inlines is for now unchanged.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@31189 268f45cc-cd09-0410-ab3c-d52691b4dbfc