Revert of webrtc: run tests in the checkout directory (patchset #1 id:1 of https://codereview.chromium.org/2229213003/ )

Reason for revert:
Breaks surprisingly many bots:
https://build.chromium.org/p/client.webrtc/builders/Linux%20Memcheck/builds/6524
https://build.chromium.org/p/client.webrtc/builders/Linux%20Asan/builds/8253
https://build.chromium.org/p/client.webrtc/builders/Linux64%20Debug/builds/8950

Original issue's description:
> webrtc: run tests in the checkout directory
>
> BUG=636080
>
> Committed: https://chromium.googlesource.com/chromium/tools/build/+/ce31e9613889dd969b66f407d57c2a1c391dffa3

TBR=phajdan.jr@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=636080

Review-Url: https://codereview.chromium.org/2232803002
66 files changed