Update idlsync.py to pull in dependencies required for chrome api generation.

third_party/chrome/tools/json_schema.py

-# Copyright (c) 2012 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 copy
-import os
-import sys
-
-import json_parse
-import schema_util
-
-def DeleteNocompileNodes(item):
-  def HasNocompile(thing):
-    return json_parse.IsDict(thing) and thing.get('nocompile', False)
-
-  if json_parse.IsDict(item):
-    toDelete = []
-    for key, value in item.items():
-      if HasNocompile(value):
-        toDelete.append(key)
-      else:
-        DeleteNocompileNodes(value)
-    for key in toDelete:
-      del item[key]
-  elif type(item) == list:
-    item[:] = [DeleteNocompileNodes(thing)
-        for thing in item if not HasNocompile(thing)]
-
-  return item
-
-def Load(filename):
-  with open(filename, 'r') as handle:
-    schemas = json_parse.Parse(handle.read())
-  return schemas
-
-# A dictionary mapping |filename| to the object resulting from loading the JSON
-# at |filename|.
-_cache = {}
-
-def CachedLoad(filename):
-  """Equivalent to Load(filename), but caches results for subsequent calls"""
-  if filename not in _cache:
-    _cache[filename] = Load(filename)
-  # Return a copy of the object so that any changes a caller makes won't affect
-  # the next caller.
-  return copy.deepcopy(_cache[filename])