Fix cit.py when ~/.chrome-infra exists but does not have infra.

cit.py

 #!/usr/bin/env python
 # Copyright (c) 2015 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.
 
 
 """Wrapper for updating and calling infra.git tools.
 
 This tool does a two things:
 * Maintains a infra.git checkout pinned at "deployed" in the home dir
@@ skipping 24 matching lines @@
   """Checks to see if we need to update the ~/.chrome-infra/infra checkout."""
   try:
     cmd = [sys.executable, GCLIENT, 'revinfo']
     subprocess.check_call(
         cmd, cwd=os.path.join(TARGET_DIR), stdout=subprocess.PIPE)
   except subprocess.CalledProcessError:
     return True  # Gclient failed, definitely need to update.
   except OSError:
     return True  # Gclient failed, definitely need to update.
 
+  if not os.path.isdir(INFRA_DIR):
+    return True
+
   local_rev = get_git_rev(INFRA_DIR, 'HEAD')
 
   subprocess.check_call(
       ['git', 'fetch', 'origin'], cwd=INFRA_DIR,
       stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
   origin_rev = get_git_rev(INFRA_DIR, 'origin/%s' % (branch,))
   return origin_rev != local_rev
 
 
 def ensure_infra(branch):
@@ skipping 53 matching lines @@
     args.args.pop(0)
   if extras:
     args.args = extras + args.args
 
   if need_to_update(args.infra_branch):
     ensure_infra(args.infra_branch)
   return run(args.args)
 
 if __name__ == '__main__':
   sys.exit(main())