[LayoutNG] Copy ShouldPaintDescendantOutlines logic for PaintBlockFlowContents

This patch copies the logic to check ShouldPaintDescendantOutlines
from BlockPainter::PaintBlockFlowContents().

Before this change, PaintPhase::kOutline and kDescendantOutlinesOnly
painted all descendants. With this change, they paint LayoutInline
descendants only, matching to the legacy behavior.

The difference was observed in
fast/block/float/float-in-float-painting.html.

Bug: 936024
Change-Id: I8f0d985b7ced9f8e1295bdb4e4a0f3763551b2c6
Reviewed-on: https://chromium-review.googlesource.com/c/1495134
Reviewed-by: Emil A Eklund <eae@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636481}
1 file changed