These aren't in use, and the original problem they were
meant to solve has been solved at the gclient.py layer 
using resource locking:
  https://codereview.chromium.org/2049583003

Bug: 773008
Change-Id: I6609f39d7f15604e0bb3d742a41c4f9fec87a57a
Reviewed-on: https://chromium-review.googlesource.com/707728Reviewed-by: Aaron Gable <agable@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Ryan Tseng <hinoka@chromium.org>