Reviewed by Antti Koivisto and Dave Hyatt.

        - fix <rdar://problem/5582961> Incorrect layout and floating object list corruption when CSS decreases a block's height

        Test: fast/block/float/overhanging-after-height-decrease.html

        * rendering/RenderBlock.cpp:
        (WebCore::RenderBlock::layoutBlock): If after calculating the height
        it turns out that there are overhanging floats that were not overhanging
        before, rescan children with overhanging floats and add them. 
        (WebCore::RenderBlock::layoutBlockChildren): Added a parameter that
        returns the lowest float bottom of any of the children.
        (WebCore::RenderBlock::addOverhangingFloats): Changed to return the
        lowest float bottom.
        * rendering/RenderBlock.h:

LayoutTests:

        Reviewed by Antti Koivisto and Dave Hyatt.

        - test for <rdar://problem/5582961> Incorrect layout and floating object list corruption when CSS decreases a block's height

        * fast/block/float/overhanging-after-height-decrease.html: Added.
        * platform/mac-leopard/fast/block: Added.
        * platform/mac-leopard/fast/block/float: Added.
        * platform/mac-leopard/fast/block/float/overhanging-after-height-decrease-expected.checksum: Added.
        * platform/mac-leopard/fast/block/float/overhanging-after-height-decrease-expected.png: Added.
        * platform/mac/fast/block/float/overhanging-after-height-decrease-expected.txt: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@27486 268f45cc-cd09-0410-ab3c-d52691b4dbfc