GitLab

- Add Polymer 3 versions of settings_page/* files to the grdp
- Autogenerate tests for Polymer 3 versions of settings-subpage and
  settings-animated-pages

Bug: 1026426
Change-Id: I73dd675aa3f2b765c1149679bd657a8d63c7aea6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2038456Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738781}