[GTK][CMake] Remove FindXt.cmake.
https://bugs.webkit.org/show_bug.cgi?id=131227

Reviewed by Anders Carlsson.

.:

Xt is already detected by CMake's own FindX11.cmake, so there is no need to keep a custom FindXt.cmake around.

* Source/cmake/FindXt.cmake: Removed.
* Source/cmake/OptionsGTK.cmake:

Source/WebCore:

* PlatformGTK.cmake: Use FindX11.cmake's Xt variables instead of our own FindXt.cmake's ones.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@166780 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[CSSRegions] Region's behaviour not updated when becoming valid from invalid
https://bugs.webkit.org/show_bug.cgi?id=131211

Reviewed by Andrei Bucur.

Source/WebCore:

When a region becomes valid again from invalid, it was part of a dependency cycle and the dependency cycle was broken,
it needs to behave like a valid region again: if it has autoheight then it should compute its height based on the
named flow content, if it has region styling then it should apply the additional style to the flowed content.

Added a new method, updateRegionFlags, that is used to ensure that auto-height and region-styling flags
are properly set in several situations. Checking the behaviour, autoheight or styling, is done only
if the region is valid.

Tests: fast/regions/auto-size/autoheight-region-valid-from-invalid.html
       fast/regions/region-styling/region-withstyling-valid-from-invalid.html

* rendering/RenderNamedFlowFragment.cpp:
(WebCore::RenderNamedFlowFragment::updateRegionFlags):
(WebCore::RenderNamedFlowFragment::styleDidChange):
(WebCore::RenderNamedFlowFragment::updateRegionHasAutoLogicalHeightFlag):
(WebCore::RenderNamedFlowFragment::checkRegionStyle):
(WebCore::RenderNamedFlowFragment::attachRegion):
(WebCore::RenderNamedFlowFragment::detachRegion):
* rendering/RenderNamedFlowFragment.h:
* rendering/RenderNamedFlowThread.cpp:
(WebCore::RenderNamedFlowThread::addFragmentToNamedFlowThread):

LayoutTests:

Add tests for auto-height and region styling behaviour.

* fast/regions/auto-size/autoheight-region-valid-from-invalid-expected.html: Added.
* fast/regions/auto-size/autoheight-region-valid-from-invalid.html: Added.
* fast/regions/region-styling/region-withstyling-valid-from-invalid-expected.html: Added.
* fast/regions/region-styling/region-withstyling-valid-from-invalid.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@166781 268f45cc-cd09-0410-ab3c-d52691b4dbfc