Revert of Revert "Add (another) argument to break git locks in gclient." (patchset #1 id:1 of https://codereview.chromium.org/1865403003/ )

Reason for revert:
This revert breaks /everything/

Original issue's description:
> Revert "Add (another) argument to break git locks in gclient."
> 
> This reverts commit 51797b1d.
> 
> BUG=601564
> TBR=iannucci,dpranke,estaab,pgervais
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=299771

TBR=dpranke@google.com,estaab@chromium.org,pgervais@chromium.org,smut@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=601564

Review URL: https://codereview.chromium.org/1867843003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@299773 0039d316-1c4b-4281-b951-d872f2087c98