Create the full path instead of just the leaf directory.

tools/bisect-perf-regression.py

 #!/usr/bin/env python
 # Copyright (c) 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.
 
 """Performance Test Bisect Tool
 
 This script bisects a series of changelists using binary search. It starts at
 a bad revision where a performance metric has regressed, and asks for a last
 known-good revision. It will then binary search across this revision range by
@@ skipping 1466 matching lines @@
     True if successful, False if an error occurred.
   """
   try:
     if os.path.exists(path_to_dir):
       shutil.rmtree(path_to_dir)
   except OSError, e:
     if e.errno != errno.ENOENT:
       return False
 
   try:
-    os.mkdir(path_to_dir)
+    os.makedirs(path_to_dir)
   except OSError, e:
     if e.errno != errno.EEXIST:
       return False
 
   return True
 
 
 def RemoveBuildFiles():
   """Removes build files from previous runs."""
   if RmTreeAndMkDir(os.path.join('out', 'Release')):
@@ skipping 158 matching lines @@
 
   if not(bisect_results['error']):
     return 0
   else:
     print 'Error: ' + bisect_results['error']
     print
     return 1
 
 if __name__ == '__main__':
   sys.exit(main())