GitLab

Prefetch a URL only if it's score is more than the specified threshold.
Additionally, only the highest ranking URL is now eligible for
prefetching.

Bug: 903945
Change-Id: I6c8166e8424da8c06f093998d606e1962184d20d
TBR: ryansturm@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/1352034Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611533}