recipe engine: add tempfile and shutil modules

recipe_modules/tempfile/api.py

Index: recipe_modules/tempfile/api.py
diff --git a/recipe_modules/tempfile/api.py b/recipe_modules/tempfile/api.py
new file mode 100644
index 0000000000000000000000000000000000000000..1bbbf407013c9e5fb6e6efdf5533277b4fcc0144
--- /dev/null
+++ b/recipe_modules/tempfile/api.py
@@ -0,0 +1,19 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import contextlib
+
+from recipe_engine import recipe_api
+
+
+class TempfileApi(recipe_api.RecipeApi):
+  @contextlib.contextmanager
+  def temp_dir(self, prefix):
+    path = None
+    try:
+      path = self.m.path.mkdtemp(prefix)
+      yield path
+    finally:
+      if path:
+        self.m.shutil.rmtree(path, infra_step=True)