[Dark] Fix GTS background color

The GTS was using ColorUtils#getDefaultThemeColor() instead of
ColorUtils#getPrimaryBackgroundColor() for its background color. This
CL fixes that.

Bug: 939927
Change-Id: Ia85262c5a2917e805445960220bf1c1f548e5194
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1534347
Reviewed-by: Becky Zhou <huayinz@chromium.org>
Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
Commit-Queue: Pedro Amaral <amaralp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#643567}
1 file changed