GitLab

- Fix spacing of share target buttons.
- Add "Learn more" link. Link doesn't work, see crbug.com/1138445
- Force long filenames to wrap so that the share target list has enough
  space.

Fix: 1131292
Change-Id: I049fa8e4c8a533773906e32d36c6717c1a9c0adf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2465808Reviewed-by: James Vecore <vecore@google.com>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Curt Clemens <cclem@google.com>
Cr-Commit-Position: refs/heads/master@{#817242}