GitLab

Add integration tests for cookie persistance

The tests check that cookies are persisted (Or not) for each of the
NetworkContexts in Chrome.

Also, fix comments in NetworkContextConfigurationBrowserTests. In
particular, the System and SafeBrowsing NetworkContexts do support
cookies, they just don't support some configuration options being
tested.

Bug: 868414
Change-Id: I8542a1ff7685efcf6588b29dcb5058dd06f1ceeb
Reviewed-on: https://chromium-review.googlesource.com/1153141Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578733}