Fix for <rdar://problem/5065396> REGRESSION: leaks in 
        RenderBlock::layoutInlineChildren seen on buildbot

        This leak appeared after http://trac.webkit.org/projects/webkit/
        changeset/20188. This change shifted line boxes around in 
        removeChild(). But since removeChild() calls 
        setNeedsLayoutAndMinMaxRecalc(), all of the line boxes will be 
        removed once we actually lay out anyway. So this patch fixes the 
        leak by deleting the line boxes instead of shifting them around. 

        * editing/IndentOutdentCommand.cpp:
        (WebCore::IndentOutdentCommand::outdentParagraph): Call into 
        updateLayout(). This fixes an assertion I got in editing/
        execCommand/4976800.html This is very similar to the line box fix I 
        made recently (http://trac.webkit.org/projects/webkit/changeset/
        20177). We need to update layout before relying on VisiblePositions 
        after removing a node.
        * rendering/RenderBlock.cpp:
        (WebCore::RenderBlock::deleteLinesForBlock): New helper function 
        since this functionality is needed in three places now.
        (WebCore::RenderBlock::makeChildrenNonInline): Call into new 
        deleteLinesForBlock().
        (WebCore::RenderBlock::removeChild): Same.
        * rendering/RenderBlock.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@20220 268f45cc-cd09-0410-ab3c-d52691b4dbfc