This picks up tracing v2 to better track git performance.

Bug: 1018953
Change-Id: I13616280b534ad80eb1904ef5012c42dadb45ca4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1884704
Auto-Submit: Erik Chen <erikchen@chromium.org>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>