Revert "Migrate PrivetTrafficDetector to use NetworkConnectionTracker."

This reverts commit 9b78521765f33993e81dfba771127fe9d5eb4add.

Reason for revert: The tests for this class weren't actually running. https://crrev.com/c/1136864 breaks because of this CL when re-enabling the tests.

Original change's description:
> Migrate PrivetTrafficDetector to use NetworkConnectionTracker.
> 
> This migrates PrivetTrafficDetector from using
> net::NetworkChangeNotifier to content::NetworkConnectionTracker, which
> works with the network service enabled.
> 
> Bug: 859134
> Change-Id: I06f2ecbe142bbed9a8772f69ab109b0c0dc32581
> Reviewed-on: https://chromium-review.googlesource.com/1123681
> Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#574700}

TBR=pastarmovj@chromium.org,thestig@chromium.org,rmcelrath@chromium.org

Change-Id: I15aeff8eed59935b9640d73e95a638c9ffb35f71
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 859134
Reviewed-on: https://chromium-review.googlesource.com/1136398
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575037}
2 files changed