recipe_autoroller: use git cache

recipes/recipe_modules/recipe_autoroller/api.py

Index: recipes/recipe_modules/recipe_autoroller/api.py
diff --git a/recipes/recipe_modules/recipe_autoroller/api.py b/recipes/recipe_modules/recipe_autoroller/api.py
index 4a8defd9c5e019677ed7161294330cd27d32f2c8..84e9f84d354f899f4386ded8bc7f8460c1906ea4 100644
--- a/recipes/recipe_modules/recipe_autoroller/api.py
+++ b/recipes/recipe_modules/recipe_autoroller/api.py
@@ -163,7 +163,8 @@ class RecipeAutorollerApi(recipe_api.RecipeApi):
   def _roll_project(self, project_data, recipes_dir):
     with self.m.tempfile.temp_dir('roll_%s' % project_data['id']) as workdir:
       self.m.git.checkout(
-          project_data['repo_url'], dir_path=workdir, submodules=False)
+          project_data['repo_url'], dir_path=workdir, submodules=False,
+          use_git_cache=True)
 
       # Introduce ourselves to git - also needed for git cl upload to work.
       self.m.git(