[Autofill Views] Setting max width

* Introduces a maximum width for the Autofill dropdown.
* Creates a subclass for Warnings with styles different from regular
  rows, and introduces logic to allow the long strings inside to wrap.
  This subclass also makes click events on the warning message a
  no-op, since the warning is not meant to be interactive.
* Changes the color of the text in warnings to use a Refresh value.

Bug: 860352
Change-Id: I320949e3965faf758286af8fbdf3487e0cb91794
Reviewed-on: https://chromium-review.googlesource.com/1130106
Commit-Queue: Tommy Martino <tmartino@chromium.org>
Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575456}
5 files changed