commit f3226a4f280b20eb00024d724b9e70ec1edc2e33
author dominickn <dominickn@chromium.org> Wed Sep 30 01:30:48 2015
committer Commit bot <commit-bot@chromium.org> Wed Sep 30 01:31:33 2015
tree 8f316c77ebfb67994e23288565c492ea9acb9f44
parent c42adedd646d50a54a467e0590160fe939f58ab6

Implement a site engagement score based on time-on-site.

Time spent on site is an important indicator of how important an origin
is to a user. This CL detects time on site by registering callbacks to
handle user input, using any mouse or keypress events as a proxy for
a user spending time on the site. Input events are checked for at
regular intervals, with site engagement updated if input has been
present in each interval.

BUG=464234

Review URL: https://codereview.chromium.org/1338603002

Cr-Commit-Position: refs/heads/master@{#351465}