Add a family of git-commands to assist with the management of multiple CLs/branches.

git-rebase-update - ensure all branches are up to date
git-new-branch - create branches
git-rename-branch - rename a branch while preserving parentage relationships
git-reparent-branch - change the parent of a branch, including rebasing it correctly onto that new parent.
git-squash-branch - collapse a branch into a single commit
git-upstream-diff - show the diff between the current branch and it's upstream branch
git-mark-merge-base - explicitly set what you want the above tools to consider the merge-base for the current branch.

R=agable@chromium.org, hinoka@chromium.org, stip@chromium.org, szager@chromium.org
BUG=261738

Review URL: https://codereview.chromium.org/184253003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@259520 0039d316-1c4b-4281-b951-d872f2087c98

git_freezer.py

@@ -1,73 +1,33 @@
 #!/usr/local/bin/python
+# Copyright 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.
+
 import sys
-import re
 import optparse
 
 import subcommand
-import subprocess2
 
-from git_common import run, stream
+from git_common import freeze, thaw
 
-FREEZE = 'FREEZE'
-SECTIONS = {
-  'indexed': 'soft',
-  'unindexed': 'mixed'
-}
-MATCHER = re.compile(r'%s.(%s)' % (FREEZE, '|'.join(SECTIONS)))
-
-
-def freeze():
-  took_action = False
-
-  try:
-    run('commit', '-m', FREEZE + '.indexed')
-    took_action = True
-  except subprocess2.CalledProcessError:
-    pass
-
-  try:
-    run('add', '-A')
-    run('commit', '-m', FREEZE + '.unindexed')
-    took_action = True
-  except subprocess2.CalledProcessError:
-    pass
-
-  if not took_action:
-    return 'Nothing to freeze.'
-
-
-def thaw():
-  took_action = False
-  for sha in (s.strip() for s in stream('rev-list', 'HEAD').xreadlines()):
-    msg = run('show', '--format=%f%b', '-s', 'HEAD')
-    match = MATCHER.match(msg)
-    if not match:
-      if not took_action:
-        return 'Nothing to thaw.'
-      break
-
-    run('reset', '--' + SECTIONS[match.group(1)], sha)
-    took_action = True
-
-
-def CMDfreeze(parser, args):  # pragma: no cover
+def CMDfreeze(parser, args):
   """Freeze a branch's changes."""
   parser.parse_args(args)
   return freeze()
 
 
-def CMDthaw(parser, args):  # pragma: no cover
+def CMDthaw(parser, args):
   """Returns a frozen branch to the state before it was frozen."""
   parser.parse_args(args)
   return thaw()
 
 
-def main():  # pragma: no cover
+def main():
   dispatcher = subcommand.CommandDispatcher(__name__)
   ret = dispatcher.execute(optparse.OptionParser(), sys.argv[1:])
   if ret:
     print ret
 
 
-if __name__ == '__main__':  # pragma: no cover
-  main()
+if __name__ == '__main__':
+  main()