GitLab

For foreground tabs the blink scheduler handles idle time.

BUG=404850,397026
R=hpayer@chromium.org,sullivan@chromium.org,reveman@chromium.org,ulan@chromium.org,dcheng@chromium.org

Review URL: https://codereview.chromium.org/603083002

Cr-Commit-Position: refs/heads/master@{#297025}