This reverts commit c63d9552.

Reason for revert: Test fails on Win7

Original change's description:
> Add system util to execute app and retrieve its output
> 
> 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>

TBR=jmadill@google.com,syoussefi@chromium.org,jmadill@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: angleproject:3125, angleproject:3168
Change-Id: I389c0ee639c7c0176c87abe92fc88f99d1b20cc4
Reviewed-on: https://chromium-review.googlesource.com/c/1487104Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>