Reviewed by John Sullivan.

        - fix <rdar://problem/5805070> CrashTracer: [USER] 33 crashes in Safari at com.apple.WebCore: WebCore::FrameView::layout + 431

        Test: fast/dynamic/subtree-parent-static-y.html

        * rendering/RenderObject.cpp:
        (WebCore::RenderObject::markContainingBlocksForLayout): Avoid calling
        this method on the parent if the parent is the new layout subtree root,
        which would result in marking all the way to the top, when it should
        actually do nothing.

LayoutTests:

        Reviewed by John Sullivan.

        - test for <rdar://problem/5805070> CrashTracer: [USER] 33 crashes in Safari at com.apple.WebCore: WebCore::FrameView::layout + 431

        * fast/dynamic/subtree-parent-static-y.html: Added.
        * platform/mac/fast/dynamic/subtree-parent-static-y-expected.checksum: Added.
        * platform/mac/fast/dynamic/subtree-parent-static-y-expected.png: Added.
        * platform/mac/fast/dynamic/subtree-parent-static-y-expected.txt: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@31153 268f45cc-cd09-0410-ab3c-d52691b4dbfc