autotest: clean tree during deploy_server_local

BUG=chromium:718268
TEST=Local test

Change-Id: I8fd137c907d7d85cfd16c2da86590c8f72c6ddd7
Reviewed-on: https://chromium-review.googlesource.com/495569
Commit-Ready: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
diff --git a/site_utils/deploy_server_local.py b/site_utils/deploy_server_local.py
index f4c85a6..bc6e3de 100755
--- a/site_utils/deploy_server_local.py
+++ b/site_utils/deploy_server_local.py
@@ -78,6 +78,8 @@
     @raises subprocess.CalledProcessError on a repo command failure.
     """
     subprocess.check_output(['git', 'reset', '--hard'])
+    # Forcefully blow away any non-gitignored files in the tree.
+    subprocess.check_output(['git', 'clean', '-fd'])
     out = subprocess.check_output(['repo', 'status'], stderr=subprocess.STDOUT)
     out = strip_terminal_codes(out).strip()