The removal of this preference was botched, all other surrounding plumbing changes appear to be working okay. The ability to use prefs to control this stylesheet might be useful in the future, so perhaps this is one of those "if it ain't broke, don't fix it" bugs where leaving well enough alone in the first place would have been the best choice.
Part 1: Remove current table item, as it's never set.
Part 2: Get rid of generic table painting code, and handle each class separately.
Part 4: Hoist outline skipping into col(group) frame code.
Part 5: Skip box-shadow for table column and column groups.
Part 6: Store column and column group backgrounds separately, and then append them before the rest of the table contents.
Part 7: Pass rects in display list coordinates to AppendBackgroundItemsToTop.
Part 8: Create column and column group background display items as part of the cell's BuildDisplayList.
Part 9: Used cached values instead of calling nsDisplayListBuilder::ToReferenceFrame when possible, since it can be expensive when the requested frame isn't the builder's current frame.
Part 10: Make sure we build display items for table parts where only the normal position is visible, since we may need to create background items for ancestors at that position.
Part 11: Create an AutoBuildingDisplayList when we create background items for table columns and column groups, so that we initialize the invalidation state correctly.
athenian200
win7-7
Moonchild
wolfbeast
Gaming4JC
Matt A. Tobin