[LayoutNG] Fix crash in PaintController::FinishCycle

According to wangxianzhu@, the crash is specifically about
a missing setNeedsRepaint of the painting layer when a
DispalyItemClient is missing.

This patch adds that, when the root NGPaintFragment of
inline formatting context (LayoutBlockFlow) is destroyed.

This is a speculative fix.

Bug: 866771, 906756
Change-Id: I9a833671ef67079d06a96f42aa47a9d277d3b77c
Reviewed-on: https://chromium-review.googlesource.com/c/1410953
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623078}
1 file changed