Bug 1644264 - Mark frame with text-overflow ellipsis as modified when overflow...
Bug 1644264 - Mark frame with text-overflow ellipsis as modified when overflow changes. r=mattwoodrow, a=jcristau This prevents us not descending to rebuild the display list if the overflow changes during an intermediate layout like a flex layout. To capture Matrix discussion: This is a bit unfortunate, but the idea is that text-overflow is usually pretty small (at most one line of content) so we can probably live with this. An alternative would be to do something like nsDisplayListBuilder::MarkFrameForDisplayIfVisible, which could work as well. Note that this is a bit of a speculative fix because neither me or Cameron have been able to reproduce the issue in local builds (I tried all the combinations of gfx-things that I could think about). :-( If this doesn't fix it on next nightly, we should back out and try to repro some other way, I guess. But the hypothesis of why it happens makes sense to me, and if it's correct it should fix the issue. Differential Revision: https://phabricator.services.mozilla.com/D79009