GitLab

 - Add aria-label and title attributes were missing.
 - Fix incorrect aria-label$=... assignments where no
   Polymer bindings are involved.

Bug: 1123470
Change-Id: I0d6c33c9338a1494d47e249bd71885f4614566fb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2418471
Commit-Queue: dpapad <dpapad@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808516}