https://bugs.webkit.org/show_bug.cgi?id=120135

Source/WebCore:

Reviewed by Jer Noble.

When removing a filter on an inline child of a compositing layer,
the inline loses its RenderLayer and compositing layer, but we fail to
repaint the compositing layer that the inline is now painting into.

This worked correctly for opacity, because opacity toggles cause
layouts (which then paint the correct layer), so do the same for filters.

Test: css3/filters/remove-filter-repaint.html

* rendering/style/RenderStyle.cpp:
(WebCore::RenderStyle::changeRequiresLayout): Return true if we toggled
between having filters and not. Drive-by cleanup, making use of new convenience
function for hasOpacity().
* rendering/style/StyleRareNonInheritedData.cpp:
(WebCore::StyleRareNonInheritedData::hasFilters): Returns true if we have any
filters.
* rendering/style/StyleRareNonInheritedData.h:
(WebCore::StyleRareNonInheritedData::hasOpacity): Convenience function that
returns true if opacity is < 1.

LayoutTests:

Reviewed by Jer Noble.

Ref test for removing a filter on an inline.

* css3/filters/remove-filter-repaint-expected.html: Added.
* css3/filters/remove-filter-repaint.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154430 268f45cc-cd09-0410-ab3c-d52691b4dbfc