Force-restart adb when setting up the device at the beginning of the run.
Force-restart adb when setting up the device at the beginning of the run.

This ports a change over from chromium r229931 / codereview.chromium.org/32163002
to forcibly restart adb on each connected device at the beginning of each webkit_tests
in the hopes of making it more reliable.

TBR=bulach@chromium.org, tonyg@chromium.org, peter@chromium.org
BUG=305040

Review URL: https://codereview.chromium.org/83753004

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@163674 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs