GitLab

Add browsertests that check the interaction between the site
engagement service and top hosts provider.

Change-Id: I8161c9c823ff98027ddb5674fead173606232ed3
Bug: 999541
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1790289Reviewed-by: Michael Crouse <mcrouse@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#694958}