OneGoogleBarFetcher: abandon ongoing request on Refresh

It's possible that something changed in the meantime, e.g. cookies, so
it's safer to start a fresh request.

Bug: 583292
Change-Id: I848c09d0fa3430efee4e4a499a5d936a23170c26
Reviewed-on: https://chromium-review.googlesource.com/606287
Reviewed-by: Chris Pickel <sfiera@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492920}
3 files changed