This is an optimization to avoid painting backgrounds
that are obscured. It's a lot of complexity that it's
not clear we'll need given that we're using a GL backend.
Also, we can add it back in more easily/efficiently in the future
once we have a display list architecture.
This also means we can remove the needsPaintInvalidation
dirty bit and some opacity information on filters.
R=esprehn@chromium.org
Review URL: https://codereview.chromium.org/856563006
The only thing they're used for now is to clear the
background obscuration state on RenderBox. They're
also used in RenderLayerModelObject::styleWillChange,
but that usage seems like a huge premature optimization.
Unfortunately, the RenderBox one walks up the ancestor
chain, so it's likely a necessary performance optimization.
R=esprehn@chromium.org
Review URL: https://codereview.chromium.org/851033002
This caused us to lose our gn check certification. :(
Turns out gn check was just ignoring all the header
paths it didn't understand and so gn check passing
for sky wasn't meaning much. I tried to straighten
out some of the mess in this CL, but its going to take
several more rounds of massaging before gn check
passes again. On the bright side (almost) all of
our headers are absolute now. Turns out my script
(attached to the bug) didn't notice ../ includes
but I'll fix that in the next patch.
R=abarth@chromium.org
BUG=435361
Review URL: https://codereview.chromium.org/746023002
