DO NOT MERGE: Move PinningNetworkCallback out to a new NetworkPinner class. am: 502d7cd551  -s ours am: 96b3d0a1bb
am: fc79ffdbe6  -s ours

* commit 'fc79ffdbe641a470e364cf205616879cb87e3eb1':
  DO NOT MERGE: Move PinningNetworkCallback out to a new NetworkPinner class.