Fix webkitpy scm_unittests so that they pass again.

Tools/Scripts/webkitpy/common/checkout/scm/scm_unittest.py

 # Copyright (C) 2009 Google Inc. All rights reserved.
 # Copyright (C) 2009 Apple Inc. All rights reserved.
 # Copyright (C) 2011 Daniel Bates (dbates@intudata.com). All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #    * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
@@ skipping 362 matching lines @@
     def tearDown(self):
         super(GitSVNTest, self).tearDown()
         self._tear_down_svn_checkout()
         self._tear_down_gitsvn_checkout()
 
     def _set_up_gitsvn_checkout(self):
         self.git_checkout_path = self._mkdtemp(suffix="git_test_checkout")
         # --quiet doesn't make git svn silent
         self._run_silent(['git', 'svn', 'clone', '-T', 'trunk', self.svn_repo_url, self.git_checkout_path])
         self._chdir(self.git_checkout_path)
+        self.git_v2 = self._run(['git', '--version']).startswith('git version 2')
+        if self.git_v2:
+            # The semantics of 'git svn clone -T' changed in v2 (apparently), so the branch names are different.
+            # This works around it, for compatibility w/ v1.
+            self._run_silent(['git', 'branch', 'trunk', 'origin/trunk'])
 
     def _tear_down_gitsvn_checkout(self):
         self._rmtree(self.git_checkout_path)
 
     def test_detection(self):
         self.assertEqual(self.scm.display_name(), "git")
         self.assertEqual(self.scm.supports_local_commits(), True)
 
     def test_read_git_config(self):
         key = 'test.git-config'
@@ skipping 86 matching lines @@
         self._write_text_file('test_file', 'changed test content')
         self.assertTrue(self.scm.has_working_directory_changes())
         self.assertRaises(ScriptError, self.scm.commit_locally_with_message, 'no working copy changes', False)
 
     def _test_upstream_branch(self):
         self._run(['git', 'checkout', '-t', '-b', 'my-branch'])
         self._run(['git', 'checkout', '-t', '-b', 'my-second-branch'])
         self.assertEqual(self.scm._upstream_branch(), 'my-branch')
 
     def test_remote_branch_ref(self):
-        self.assertEqual(self.scm._remote_branch_ref(), 'refs/remotes/trunk')
+        remote_branch_ref = self.scm._remote_branch_ref()
+        if self.git_v2:
+            self.assertEqual(remote_branch_ref, 'refs/remotes/origin/trunk')
+        else:
+            self.assertEqual(remote_branch_ref, 'refs/remotes/trunk')
 
     def test_create_patch_local_plus_working_copy(self):
         self._one_local_commit_plus_working_copy_changes()
         patch = self.scm.create_patch()
         self.assertRegexpMatches(patch, r'test_file_commit1')
         self.assertRegexpMatches(patch, r'test_file_commit2')
 
     def test_create_patch(self):
         self._one_local_commit_plus_working_copy_changes()
         patch = self.scm.create_patch()
@@ skipping 185 matching lines @@
         scm = self.make_scm()
         scm.find_checkout_root = lambda path: ''
         scm._run_git = lambda args: 'Date: 2013-02-08 08:05:49 +0000'
         self.assertEqual(scm.timestamp_of_revision('some-path', '12345'), '2013-02-08T08:05:49Z')
 
         scm._run_git = lambda args: 'Date: 2013-02-08 01:02:03 +0130'
         self.assertEqual(scm.timestamp_of_revision('some-path', '12345'), '2013-02-07T23:32:03Z')
 
         scm._run_git = lambda args: 'Date: 2013-02-08 01:55:21 -0800'
         self.assertEqual(scm.timestamp_of_revision('some-path', '12345'), '2013-02-08T09:55:21Z')