merge_pr_47012

Reland "[text-decorations] Fix a crash for ::first-line"

This is a reland of commit c9d2271396f178e2c0747f2ef2ac727d8a02f9d1

The original CL hits a DCHECK in the
linux-autofill-captured-sites-rel bots. This CL changes to
push 2 decoration boxes only when the conditions are known,
and to fall back to 1 decoration box in other cases.

This CL also puts the changes under a runtime flag.

Original change's description:

[text-decorations] Fix a crash for ::first-line

This patch fixes a crash when text-decoration is applied to
::first-line.

Fixed: 345562934
Change-Id: If26564ca3dcb913236771ef4a634928485b68eca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5677308
Reviewed-by: Kent Tamura tkent@chromium.org
Auto-Submit: Koji Ishii kojii@chromium.org
Commit-Queue: Koji Ishii kojii@chromium.org
Cr-Commit-Position: refs/heads/main@{#1323270}

Change-Id: Ifb27df1bfd8e9d0a9dc37a1f18d27a6c9488cc29
Fixed: 345562934
Cq-Include-Trybots: luci.chrome.try:linux-autofill-captured-sites-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5678276
Reviewed-by: Kent Tamura tkent@chromium.org
Auto-Submit: Koji Ishii kojii@chromium.org
Commit-Queue: Kent Tamura tkent@chromium.org
Cr-Commit-Position: refs/heads/main@{#1323484}