Add input_api.json to presubmit checks.

tests/trychange_unittest.py

 #!/usr/bin/python
 # Copyright (c) 2010 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.
 
 """Unit tests for trychange.py."""
 
 # Fixes include path.
 from super_mox import mox, SuperMoxTestBase
 
@@ skipping 24 matching lines @@
     self.options.exclude = []
 
 
 class TryChangeUnittest(TryChangeTestsBase):
   """General trychange.py tests."""
   def testMembersChanged(self):
     members = [
       'EscapeDot', 'GIT', 'GuessVCS', 'GetMungedDiff',
       'HELP_STRING', 'InvalidScript', 'NoTryServerAccess', 'PrintSuccess',
       'SCM', 'SVN', 'TryChange', 'USAGE',
-      'breakpad', 'datetime', 'errno', 'gclient_utils', 'getpass', 'logging',
-      'optparse', 'os', 'posixpath', 're', 'scm', 'shutil', 'sys', 'tempfile',
-      'urllib',
+      'breakpad', 'datetime', 'errno', 'gclient_utils', 'getpass', 'json',
+      'logging', 'optparse', 'os', 'posixpath', 're', 'scm', 'shutil', 'sys',
+      'tempfile', 'urllib',
     ]
     # If this test fails, you should add the relevant test.
     self.compareMembers(trychange, members)
 
 
 class SVNUnittest(TryChangeTestsBase):
   """trychange.SVN tests."""
   def testMembersChanged(self):
     members = [
       'AutomagicalSettings', 'GclStyleSettings', 'GclientStyleSettings',
@@ skipping 39 matching lines @@
     self.mox.ReplayAll()
     git = trychange.GIT(self.options, self.fake_root)
     self.assertEqual(git.GetFileNames(), self.expected_files)
     self.assertEqual(git.checkout_root, self.fake_root)
     self.assertEqual(git.GenerateDiff(), 'A diff')
 
 
 if __name__ == '__main__':
   import unittest
   unittest.main()