GitLab

In overview, the split view drag indicator always has an opacity of 18%,
whereas the specification calls for 30% when indicating where to drag a
window, and 18% when serving as a preview of snapped window bounds:
https://mccanny.users.x20web.corp.google.com/www/splitscreen-motion/index.html#indicator-expand

Test: manual
Bug: 808283
Change-Id: I4cbf1230f34d3b90389c60d8fc909298b8b9d386
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1500912
Commit-Queue: Avery Musbach <amusbach@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637549}