Garbage texture data with composited table row

Garbage texture data with composited table row
https://bugs.webkit.org/show_bug.cgi?id=148984

Reviewed by Zalan Bujtas.
Source/WebCore:

Don't pretend to know if the layer for a table header, section or cell is
opaque, since table painting is special.

Test: compositing/contents-opaque/table-parts.html

* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::backgroundIsKnownToBeOpaqueInRect):

LayoutTests:

* compositing/contents-opaque/table-parts-expected.txt: Added.
* compositing/contents-opaque/table-parts.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@190820 268f45cc-cd09-0410-ab3c-d52691b4dbfc