Quota: Add a test for the Quota expansion experiment.

For more context regarding the experiment, see: https://crrev.com/c/1401568

Change-Id: I2bc2a868dde80aab321905a47100e5480f4e8024
Bug: 919693
Reviewed-on: https://chromium-review.googlesource.com/c/1433132
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Reviewed-by: Eric Seckler <eseckler@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Reviewed-by: Sean Topping <seantopping@chromium.org>
Reviewed-by: Finnur Thorarinsson <finnur@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631132}
13 files changed