Add --upstream option to gclient to scrape git checkouts back to upstream state.

This will be used on the bots when calling apply_patch, which commits to git
repos.

R=dpranke@chromium.org,szager@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/18006002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@209040 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/tests/gclient_scm_test.py b/tests/gclient_scm_test.py
index 6cc7927..9d25d7b 100755
--- a/tests/gclient_scm_test.py
+++ b/tests/gclient_scm_test.py
@@ -684,6 +684,7 @@
       self.force = False
       self.reset = False
       self.nohooks = False
+      self.upstream = False
       self.merge = False
       self.jobs = 1
       self.delete_unversioned_trees = False