Fix python scripts in src/tools/

tools/sync-webkit-git.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.
 
 """Update third_party/WebKit using git.
 
 Under the assumption third_party/WebKit is a clone of git.webkit.org,
 we can use git commands to make it match the version requested by DEPS.
 
 See http://code.google.com/p/chromium/wiki/UsingWebKitGit for details on
 how to use this.
 """
 
 import logging
 import optparse
 import os
 import re
 import subprocess
 import sys
 
+
 def RunGit(command):
   """Run a git subcommand, returning its output."""
   # On Windows, use shell=True to get PATH interpretation.
   command = ['git'] + command
   logging.info(' '.join(command))
   shell = (os.name == 'nt')
   proc = subprocess.Popen(command, shell=shell, stdout=subprocess.PIPE)
   out = proc.communicate()[0].strip()
   logging.info('Returned "%s"' % out)
   return out
 
+
 def GetOverrideShortBranchName():
   """Returns the user-configured override branch name, if any."""
   override_config_name = 'chromium.sync-branch'
   return RunGit(['config', '--get', override_config_name])
 
+
 def GetGClientBranchName():
   """Returns the name of the magic branch that lets us know that DEPS is
   managing the update cycle."""
   # Is there an override branch specified?
   override_branch_name = GetOverrideShortBranchName()
   if not override_branch_name:
     return 'refs/heads/gclient' # No override, so return the default branch.
 
   # Verify that the branch from config exists.
   ref_branch = 'refs/heads/' + override_branch_name
   current_head = RunGit(['show-ref', '--hash', ref_branch])
   if current_head:
     return ref_branch
 
   # Inform the user about the problem and how to fix it.
   print ("The specified override branch ('%s') doesn't appear to exist." %
          override_branch_name)
   print "Please fix your git config value '%s'." % overide_config_name
   sys.exit(1)
 
+
 def GetWebKitRev():
   """Extract the 'webkit_revision' variable out of DEPS."""
   locals = {'Var': lambda _: locals["vars"][_],
             'From': lambda *args: None}
   execfile('DEPS', {}, locals)
   return locals['vars']['webkit_revision']
 
+
 def FindSVNRev(target_rev):
   """Map an SVN revision to a git hash.
   Like 'git svn find-rev' but without the git-svn bits."""
 
   # We iterate through the commit log looking for "git-svn-id" lines,
   # which contain the SVN revision of that commit.  We can stop once
   # we've found our target (or hit a revision number lower than what
   # we're looking for, indicating not found).
 
   target_rev = int(target_rev)
@@ skipping 24 matching lines @@
           print ("WARNING: r%d not found, so using next nearest earlier r%d" %
                  (target_rev, rev))
         return commit
       else:
         saw_later = True
 
   print "Error: reached end of log without finding commit info."
   print "Something has likely gone horribly wrong."
   return None
 
+
 def GetRemote():
   branch = GetOverrideShortBranchName()
   if not branch:
     branch = 'gclient'
 
   remote = RunGit(['config', '--get', 'branch.' + branch + '.remote'])
   if remote:
     return remote
   return 'origin'
 
+
 def UpdateGClientBranch(webkit_rev, magic_gclient_branch):
   """Update the magic gclient branch to point at |webkit_rev|.
 
   Returns: true if the branch didn't need changes."""
   target = FindSVNRev(webkit_rev)
   if not target:
     print "r%s not available; fetching." % webkit_rev
     subprocess.check_call(['git', 'fetch', GetRemote()],
                           shell=(os.name == 'nt'))
     target = FindSVNRev(webkit_rev)
   if not target:
     print "ERROR: Couldn't map r%s to a git revision." % webkit_rev
     sys.exit(1)
 
   current = RunGit(['show-ref', '--hash', magic_gclient_branch])
   if current == target:
     return False  # No change necessary.
 
   subprocess.check_call(['git', 'update-ref', '-m', 'gclient sync',
                          magic_gclient_branch, target],
                          shell=(os.name == 'nt'))
   return True
 
+
 def UpdateCurrentCheckoutIfAppropriate(magic_gclient_branch):
   """Reset the current gclient branch if that's what we have checked out."""
   branch = RunGit(['symbolic-ref', '-q', 'HEAD'])
   if branch != magic_gclient_branch:
     print "We have now updated the 'gclient' branch, but third_party/WebKit"
     print "has some other branch ('%s') checked out." % branch
     print "Run 'git checkout gclient' under third_party/WebKit if you want"
     print "to switch it to the version requested by DEPS."
     return 1
 
   if subprocess.call(['git', 'diff-index', '--exit-code', '--shortstat',
                       'HEAD'], shell=(os.name == 'nt')):
     print "Resetting tree state to new revision."
     subprocess.check_call(['git', 'reset', '--hard'], shell=(os.name == 'nt'))
 
+
 def main():
   parser = optparse.OptionParser()
   parser.add_option('-v', '--verbose', action='store_true')
   options, args = parser.parse_args()
   if options.verbose:
     logging.basicConfig(level=logging.INFO)
   if not os.path.exists('third_party/WebKit/.git'):
     if os.path.exists('third_party/WebKit'):
       print "ERROR: third_party/WebKit appears to not be under git control."
     else:
       print "ERROR: third_party/WebKit could not be found."
       print "Did you run this script from the right directory?"
 
     print "See http://code.google.com/p/chromium/wiki/UsingWebKitGit for"
     print "setup instructions."
     return 1
 
   webkit_rev = GetWebKitRev()
   print 'Desired revision: r%s.' % webkit_rev
   os.chdir('third_party/WebKit')
   magic_gclient_branch = GetGClientBranchName()
   changed = UpdateGClientBranch(webkit_rev, magic_gclient_branch)
   if changed:
     return UpdateCurrentCheckoutIfAppropriate(magic_gclient_branch)
   else:
     print "Already on correct revision."
   return 0
 
+
 if __name__ == '__main__':
   sys.exit(main())