GitLab

Make these changes according to UI review:
1. Have both shadow and rouned corner. This is done by using
   views::BubbleBorder so that it looks closer to other such widgets,
   e.g. sharesheet.
2. Change primary text color to GoogleGrey900, secondary text color to
   GoogleGrey700.
3. Adjust vertical spacing after title, origin name prompt and PIN input
   field to match start screen spec.

Bug: b:156258540, b:144861739
Change-Id: Ie84ed82d6fed17c63d7dec49a18fa75f42599e25
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2523520Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Yicheng Li <yichengli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825132}