Add input_api.json to presubmit checks.

presubmit_support.py

 #!/usr/bin/python
 # Copyright (c) 2006-2009 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.
 
 """Enables directory-specific presubmit checks to run at upload and/or commit.
 """
 
 __version__ = '1.3.4'
 
@@ skipping 16 matching lines @@
 import subprocess  # Exposed through the API.
 import sys  # Parts exposed through API.
 import tempfile  # Exposed through the API.
 import time
 import traceback  # Exposed through the API.
 import types
 import unittest  # Exposed through the API.
 import urllib2  # Exposed through the API.
 import warnings
 
+# json may not be available.
+try:
+  import simplejson as json
+except ImportError:
+  try:
+    import json
+  except ImportError:
+    json = None
+
 # Local imports.
 import gcl
 import gclient_utils
 import presubmit_canned_checks
 import scm
 
 
 # Ask for feedback only once in program lifetime.
 _ASKED_FOR_FEEDBACK = False
 
@@ skipping 142 matching lines @@
     # Version number of the presubmit_support script.
     self.version = [int(x) for x in __version__.split('.')]
     self.change = change
     self.is_committing = is_committing
 
     # We expose various modules and functions as attributes of the input_api
     # so that presubmit scripts don't have to import them.
     self.basename = os.path.basename
     self.cPickle = cPickle
     self.cStringIO = cStringIO
+    self.json = json
     self.os_path = os.path
     self.pickle = pickle
     self.marshal = marshal
     self.re = re
     self.subprocess = subprocess
     self.tempfile = tempfile
     self.traceback = traceback
     self.unittest = unittest
     self.urllib2 = urllib2
 
@@ skipping 840 matching lines @@
                                options.commit,
                                options.verbose,
                                sys.stdout,
                                sys.stdin,
                                options.default_presubmit,
                                options.may_prompt)
 
 
 if __name__ == '__main__':
   sys.exit(Main(sys.argv))