fix some bench rebase tool problems.

experimental/benchtools/greenify.py

-#!/usr/bin/python2.7
+#!/usr/bin/env python
 
+
+# Copyright (c) 2014 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.
+
+
 """greenify.py: standalone script to correct flaky bench expectations.
-   Usage:
-     Copy script to a separate dir outside Skia repo. The script will create a
-         skia dir on the first run to host the repo, and will create/delete temp
-         dirs as needed.
-     ./greenify.py --url <the stdio url from failed CheckForRegressions step>
+
+    Requires Rietveld credentials on the running machine.
+
+    Usage:
+      Copy script to a separate dir outside Skia repo. The script will create a
+          skia dir on the first run to host the repo, and will create/delete
+          temp dirs as needed.
+      ./greenify.py --url <the stdio url from failed CheckForRegressions step>
 """
 
 import argparse
 import filecmp
 import os
 import re
 import shutil
 import subprocess
 import time
 import urllib2
@@ skipping 121 matching lines @@
   return True
 
 
 def main():
   d = os.path.dirname(os.path.abspath(__file__))
   os.chdir(d)
   if not subprocess.call(['git', 'rev-parse'], stderr=subprocess.PIPE):
     print 'Please copy script to a separate dir outside git repos to use.'
     return
   ts_str = '%s' % time.time()
-  exp_dir = os.path.join(d, 'exp' + ts_str)
-  clean_dir(exp_dir)
 
   parser = argparse.ArgumentParser()
   parser.add_argument('--url',
                       help='Broken bench build CheckForRegressions page url.')
   parser.add_argument('--commit', action='store_true',
                       help='Whether to commit changes automatically.')
   args = parser.parse_args()
   repo_dir = os.path.join(d, 'skia')
   if not os.path.exists(repo_dir):
     os.makedirs(repo_dir)
@@ skipping 11 matching lines @@
     raise Exception('Please provide a url with broken CheckForRegressions.')
   path = args.url.split('/')
   if len(path) != 11 or not path[6].isdigit():
     raise Exception('Unexpected url format: %s' % args.url)
   bot = path[4]
   build = path[6]
   commit = False
   if args.commit:
     commit = True
 
+  exp_dir = os.path.join(d, 'exp' + ts_str)
+  clean_dir(exp_dir)
   if not widen_bench_ranges(args.url, bot, repo_dir, exp_dir):
     print 'NO bench exceptions found! %s' % args.url
   elif not git_commit_expectations(
       repo_dir, exp_dir, bot, build, commit):
     print 'ERROR uploading expectations using git.'
   elif not commit:
     print 'CL created. Please take a look at the link above.'
   else:
     print 'New bench baselines should be in CQ now.'
   delete_dirs([exp_dir])
 
 
 if __name__ == "__main__":
   main()