WebCore:

WebCore:

        Fix for http://bugs.webkit.org/show_bug.cgi?id=16935

        Fix a bug in layers where the positioned ancestor was being computed incorrectly (the root should not
        automatically be included).

        Reviewed by olliej

        Added fast/layers/positioned-inside-root-with-margins.html

        * rendering/RenderLayer.cpp:
        (WebCore::RenderLayer::stackingContext):
        (WebCore::RenderLayer::enclosingPositionedAncestor):

LayoutTests:

        http://bugs.webkit.org/show_bug.cgi?id=16935

        Reviewed by olliej

        * fast/layers/positioned-inside-root-with-margins.html: Added.
        * platform/mac/fast/layers/positioned-inside-root-with-margins-expected.checksum: Added.
        * platform/mac/fast/layers/positioned-inside-root-with-margins-expected.png: Added.
        * platform/mac/fast/layers/positioned-inside-root-with-margins-expected.txt: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@29696 268f45cc-cd09-0410-ab3c-d52691b4dbfc