depot_tools: expose paths to presubmit_support.py and upload_to_google_storage.py

recipe_modules/presubmit/api.py

Index: recipe_modules/presubmit/api.py
diff --git a/recipe_modules/presubmit/api.py b/recipe_modules/presubmit/api.py
index 1ecf12986821dc186c30fb0d40a05b07f6e0788e..31fe1d976a60fe91bf4c43d6695ddd6281672d1e 100644
--- a/recipe_modules/presubmit/api.py
+++ b/recipe_modules/presubmit/api.py
@@ -5,6 +5,10 @@
 from recipe_engine import recipe_api
 
 class PresubmitApi(recipe_api.RecipeApi):
+  @property
+  def presubmit_support_path(self):
+    return self.package_repo_resource('presubmit_support.py')
+
   def __call__(self, *args, **kwargs):
     """Return a presubmit step."""
 
@@ -16,5 +20,4 @@ class PresubmitApi(recipe_api.RecipeApi):
         kwargs['env']['PATH'], str(self._module.PACKAGE_REPO_ROOT)])
 
     return self.m.python(
-        name, self.package_repo_resource('presubmit_support.py'), list(args),
-        **kwargs)
+        name, self.presubmit_support_path, list(args), **kwargs)