This will be useful to run external applications, such as benchmarks,
and process their output.

Bug: angleproject:3125
Change-Id: Ic13c69f2e034f4b47498fb2f299c62423c355c4a
Reviewed-on: https://chromium-review.googlesource.com/c/1452534
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@google.com>