[Explore sites]: Add all the missing cases for getVariation.

Bug: 919454
Change-Id: Iabb79625a254bb619564eef676b6f74579007dcb
Reviewed-on: https://chromium-review.googlesource.com/c/1398308
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Cathy Li <chili@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620873}
3 files changed