Add Paths as first-class types in configs.

scripts/slave/recipe_modules/json/api.py

 # 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.
 
 import functools
 import contextlib
 import json
 
 from cStringIO import StringIO
 
 from slave import recipe_api
 from slave import recipe_util
+from slave import recipe_config_types
 
 from .util import TestResults
 
 class StringListIO(object):
   def __init__(self):
     self.lines = [StringIO()]
 
   def write(self, s):
     while s:
       i = s.find('\n')
@@ skipping 55 matching lines @@
     return TestResults(ret)
 
 
 class JsonApi(recipe_api.RecipeApi):
   def __init__(self, **kwargs):
     super(JsonApi, self).__init__(**kwargs)
     self.loads = json.loads
     @functools.wraps(json.dumps)
     def dumps(*args, **kwargs):
       kwargs['sort_keys'] = True
+      kwargs.setdefault('default', recipe_config_types.json_fixup)
       return json.dumps(*args, **kwargs)
     self.dumps = dumps
 
   @recipe_util.returns_placeholder
   def input(self, data):
     """A placeholder which will expand to a file path containing <data>."""
     return self.m.raw_io.input(self.dumps(data), '.json')
 
   @recipe_util.returns_placeholder
   def output(self):
@@ skipping 16 matching lines @@
 
     It's vastly preferable to have your recipe only pass the bare minimum
     of arguments to steps. Passing property objects obscures the data that
     the script actually consumes from the property object.
     """
     prop_str = self.dumps(dict(self.m.properties))
     return [
       '--factory-properties', prop_str,
       '--build-properties', prop_str
     ]