Remove thirdparty/unittest2 from webkitpy and require python2.7.

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 13 matching lines @@
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import atexit
 import os
 import shutil
+import unittest
 
 from webkitpy.common.system.executive import Executive, ScriptError
 from webkitpy.common.system.executive_mock import MockExecutive
 from webkitpy.common.system.filesystem import FileSystem
 from webkitpy.common.system.filesystem_mock import MockFileSystem
 from webkitpy.common.checkout.scm.detection import detect_scm_system
 from webkitpy.common.checkout.scm.git import Git, AmbiguousCommitError
 from webkitpy.common.checkout.scm.scm import SCM
 from webkitpy.common.checkout.scm.svn import SVN
-import webkitpy.thirdparty.unittest2 as unittest
 
 
 # We cache the mock SVN repo so that we don't create it again for each call to an SVNTest or GitTest test_ method.
 # We store it in a global variable so that we can delete this cached repo on exit(3).
 original_cwd = None
 cached_svn_repo_path = None
 
 @atexit.register
 def delete_cached_svn_repo_at_exit():
     if cached_svn_repo_path:
@@ skipping 640 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')