Import the testing/perf module from Chromium. We can use these perf routines to make our performance test output compatible with the Chromium perf bots. BUG=angle:744 Change-Id: I75a44786d4521fc0c7d8226f10575fcfda0fa221 Reviewed-on: https://chromium-review.googlesource.com/220360 Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>