Setup basic Runtime with properties and platform.

recipe_modules/properties/api.py

 # Copyright 2013 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 from recipe_engine import recipe_api
-from recipe_engine.types import freeze
 import collections
 
 # Use RecipeApiPlain because collections.Mapping has its own metaclass.
 # Additionally, nothing in this class is a composite_step (nothing in this class
 # is any sort of step :).
 class PropertiesApi(recipe_api.RecipeApiPlain, collections.Mapping):
   """
   Provide an immutable mapping view into the 'properties' for the current run.
 
   The value of this api is equivalent to this transformation of the legacy
   build values:
     val = factory_properties
     val.update(build_properties)
   """
 
   properties_client = recipe_api.RequireClient('properties')
 
-  def __init__(self, **kwargs):
-    super(PropertiesApi, self).__init__(**kwargs)
-    self._frozen_properties = None
-
-  @property
-  def _properties(self):
-    if self._frozen_properties is None:
-      self._frozen_properties = freeze(
-          self.properties_client.get_properties())
-    return self._frozen_properties
-
   def __getitem__(self, key):
-    return self._properties[key]
+    return self.properties_client.properties[key]
 
   def __len__(self):
-    return len(self._properties)
+    return len(self.properties_client.properties)
 
   def __iter__(self):
-    return iter(self._properties)
+    return iter(self.properties_client.properties)
 
   def legacy(self):  # pragma: no cover
     """Returns a reduced set of properties, possibly used by legacy scripts."""
 
     # Add all properties to this blacklist that are required for testing, but
     # not used by any lecacy scripts, in order to avoid vast expecation
     # changes.
     blacklist = set([
       'buildbotURL',
     ])
     return {k: v for k, v in self.iteritems() if k not in blacklist}
 
   def thaw(self):
     """Returns a vanilla python jsonish dictionary of properties."""
-    return self.properties_client.get_properties()
+    return self.properties_client.mutable_properties()