[Android] Fix a race condition in run_command.py.

[Android] Fix a race condition in run_command.py.

This patch makes limited changes to minimize the likelyhood of breaking
dependent scripts.

NOTRY=True
TBR=brettw@chromium.org
BUG=180587
TEST=ran run_command.RunOnce with a timeout of 0.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=190524

[frankf, 2013-03-25 21:41:57]

lgtm after trybots pass

[commit-bot: I haz the power, 2013-03-25 23:31:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/craigdh@chromium.org/13047009/1

[commit-bot: I haz the power, 2013-03-25 23:31:03]

Presubmit check for 13047009-1 failed and returned exit status 1.

INFO:root:Found 3 file(s).

Running presubmit commit checks ...
Running /b/commit-queue/workdir/chromium/PRESUBMIT.py
Running /b/commit-queue/workdir/chromium/third_party/PRESUBMIT.py

** Presubmit ERRORS **
Missing LGTM from an OWNER for these files:
    third_party/android_testrunner/README.chromium
    third_party/android_testrunner/patch.diff
    third_party/android_testrunner/run_command.py

[commit-bot: I haz the power, 2013-03-25 23:38:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/craigdh@chromium.org/13047009/1

[craigdh, 2013-03-26 00:27:57]

Committed patchset #1 manually as r190524 (presubmit successful).