GitLab

Leverage latest improvements to autogenerate WebUI .grd files for
optimized builds as well.

Also rename c/b/r/settings:build_polymer3 to :build, and
settings_v3.html to just settings.html, as there is no longer a
need to differentiate between versions.

Bug: 1132403
Change-Id: Ie7e7a06e256bab540da673f458880f8caef367df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2465505Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: dpapad <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816768}