Implemented command buffer performance test based on
LunarG samples. Includes a lot of utility functions and
should build/run on Linux, Android

Bug: angleproject:2758
Change-Id: I8606802fb3e8e0621856860c45ef50ba836c26f8
Reviewed-on: https://chromium-review.googlesource.com/1162119
Commit-Queue: Omar El Sheikh <theoking@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>