Bigger hammer: Run each command and block, without piping stdout/stderr
Bigger hammer: Run each command and block, without piping stdout/stderr

TBR=epoger
BUG=skia:1329

Review URL: https://codereview.chromium.org/199353003

google/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot