Fix python scripts in src/tools/

tools/bisect-builds.py

-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """Snapshot Build Bisect Tool
 
 This script bisects a snapshot archive using binary search. It starts at
 a bad revision (it will try to guess HEAD) and asks for a last known-good
 revision. It will then binary search across this revision range by downloading,
 unzipping, and opening Chromium for you. After testing the specific revision,
@@ skipping 26 matching lines @@
 import re
 import shutil
 import subprocess
 import sys
 import tempfile
 import threading
 import urllib
 from xml.etree import ElementTree
 import zipfile
 
+
 class PathContext(object):
   """A PathContext is used to carry the information used to construct URLs and
   paths when dealing with the storage server and archives."""
   def __init__(self, platform, good_revision, bad_revision):
     super(PathContext, self).__init__()
     # Store off the input parameters.
     self.platform = platform  # What's passed in to the '-a/--archive' option.
     self.good_revision = good_revision
     self.bad_revision = bad_revision
 
@@ skipping 202 matching lines @@
   (stdout, stderr) = subproc.communicate()
 
   os.chdir(cwd)
   try:
     shutil.rmtree(tempdir, True)
   except Exception, e:
     pass
 
   return (subproc.returncode, stdout, stderr)
 
+
 def AskIsGoodBuild(rev, status, stdout, stderr):
   """Ask the user whether build |rev| is good or bad."""
   # Loop until we get a response that we can parse.
   while True:
     response = raw_input('Revision %d is [(g)ood/(b)ad/(q)uit]: ' % int(rev))
     if response and response in ('g', 'b'):
       return response == 'g'
     if response and response == 'q':
       raise SystemExit()
 
+
 def Bisect(platform,
            good_rev=0,
            bad_rev=0,
            try_args=(),
            profile=None,
            predicate=AskIsGoodBuild):
   """Given known good and known bad revisions, run a binary search on all
   archived revisions to determine the last known good revision.
 
   @param platform Which build to download/run ('mac', 'win', 'linux64', etc.).
@@ skipping 237 matching lines @@
   print('You are probably looking for build %d.' % first_known_bad_rev)
   if last_known_good_webkit_rev != first_known_bad_webkit_rev:
     print 'WEBKIT CHANGELOG URL:'
     print WEBKIT_CHANGELOG_URL % (first_known_bad_webkit_rev,
                                   last_known_good_webkit_rev)
   print 'CHANGELOG URL:'
   print CHANGELOG_URL % (last_known_good_rev, first_known_bad_rev)
   print 'Built at revision:'
   print BUILD_VIEWVC_URL % first_known_bad_rev
 
+
 if __name__ == '__main__':
   sys.exit(main())