commit 3bcf8d7222dd8c8822840795d14da3d8fba23cff
author Aaron Leventhal <aleventhal@google.com> Wed Sep 21 22:21:48 2022
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Sep 21 22:21:48 2022
tree 27bd0a9df448514053bddd7e3a5c7d33196415fd
parent e3d880668f4f83d7fc9c57ec9060245ff0f37936

Only use document-scoped layout updates before serialization

This is a precursor for work to move a11y to RunPostLifecycleSteps()
in CL:3861311.

There is no need to force a layout on every dirty node --
WebAXObject::MaybeUpdateLayoutAndCheckValidity() does not do this currently.

The only reason to ever do this might be if we wanted updated layout
information for every content-visibility: auto object, but this is
not necessary because the a11y code already special cases
content-visibility: auto objects with stale layout by not exposing
information that requires a layout object  such as style, location and
perfect whitespace computation. If a user tries to navigate to one
of these objects (e.g. via a skip to next heading command), then it
will be scrolled into view and receive full layout at that time.

In addition, forcing a layout for every content-visibility: auto node
would cost performance, including for users of password managers, etc.
and would ruin a lot of the benefit of content-visibility.

Bug: None
Change-Id: Id5ea7939bc997d0f8b100cd02fd736f3f4f9c9ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3905906
Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1049902}