Bug=359292
Original commit: b1391c6a
Revert: 8e5f7d308fde74c52e321587649c16568e4a9644

Original commit comment:

> Now trychange can store patches in a Git repo

> A git patch repo is cloned to .git/git-try/patches-git, if was not
> cloned before. Otherwise, changes are pulled. Then a patch is committed a
> pushed.

> --revision=auto (Git only) is resolved to the revision the diff is genera
> against.

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@261247 0039d316-1c4b-4281-b951-d872f2087c98