recipe engine: add a hook for initializing recipe module with injected deps

recipe_engine/recipe_api.py

Index: recipe_engine/recipe_api.py
diff --git a/recipe_engine/recipe_api.py b/recipe_engine/recipe_api.py
index 28fd9dc20c959dcb84ef81318a79ed32afb1e954..b64a8e0da14227eb3af74075096a74d72a212303 100644
--- a/recipe_engine/recipe_api.py
+++ b/recipe_engine/recipe_api.py
@@ -1,4 +1,4 @@
-# Copyright 2013-2015 The Chromium Authors. All rights reserved.
+# Copyright 2013 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.
 
@@ -370,6 +370,13 @@ class RecipeApiPlain(object):
     # Config goes here.
     self.c = None
 
+  def initialize(self):
+    """
+    Initializes the recipe module after it has been instantiated with all
+    dependencies injected and available.
+    """
+    pass
+
   def get_config_defaults(self):  # pylint: disable=R0201
     """
     Allows your api to dynamically determine static default values for configs.