Use new common utils where possible.

slave/skia_slave_scripts/utils/git_utils.py

-#!/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.
-
-"""This module contains functions for using git."""
-
-
-import os
-import shell_utils
-
-
-GIT = 'git.bat' if os.name == 'nt' else 'git'
-
-
-def Add(addition):
-  """Run 'git add <addition>'"""
-  shell_utils.run([GIT, 'add', addition])
-
-def AIsAncestorOfB(a, b):
-  """Return true if a is an ancestor of b."""
-  return shell_utils.run([GIT, 'merge-base', a, b]).rstrip() == FullHash(a)
-
-def FullHash(commit):
-  """Return full hash of specified commit."""
-  return shell_utils.run([GIT, 'rev-parse', '--verify', commit]).rstrip()
-
-def IsMerge(commit):
-  """Return True if the commit is a merge, False otherwise."""
-  rev_parse = shell_utils.run([GIT, 'rev-parse', commit, '--max-count=1',
-                               '--no-merges'])
-  last_non_merge = rev_parse.split('\n')[0]
-  # Get full hash since that is what was returned by rev-parse.
-  return FullHash(commit) != last_non_merge
-
-def MergeAbort():
-  """Abort in process merge."""
-  shell_utils.run([GIT, 'merge', '--abort'])
-
-def ShortHash(commit):
-  """Return short hash of the specified commit."""
-  return shell_utils.run([GIT, 'show', commit, '--format=%h', '-s']).rstrip()
-
-def GetRemoteMasterHash(git_url):
-  return shell_utils.run([GIT, 'ls-remote', git_url, '--verify',
-                          'refs/heads/master'])