GitLab

[EoC] Updates to fetch triggering

* Tracks all the tabs for non empty paint
* Triggers a fetch when the visible tab is 10 seconds past the non
  empty paint.

Bug: 824188
Change-Id: I7a26353eafe5efa39c5406040278159b9c3a3334
Reviewed-on: https://chromium-review.googlesource.com/1008276
Commit-Queue: Filip Gorski <fgorski@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550404}