Add support for git_cl_tests on Windows platform

Change-Id: I9d3d084e7f48ab991db3db16873f030890ad72d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2108981Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

PRESUBMIT.py

@@ -80,7 +80,6 @@ def CommonChecks(input_api, output_api, tests_to_black_list, run_on_python3):
     print('Warning: skipping most unit tests on Windows')
     tests_to_black_list = [
         r'.*auth_test\.py$',
-        r'.*git_cl_test\.py$',
         r'.*git_common_test\.py$',
         r'.*git_hyper_blame_test\.py$',
         r'.*git_map_test\.py$',

gerrit_util.py

@@ -206,7 +206,7 @@ class CookiesAuthenticator(Authenticator):
       return subprocess2.check_output(
           ['git', 'config', '--path', 'http.cookiefile']).strip()
     except subprocess2.CalledProcessError:
-      return os.path.join(os.environ['HOME'], '.gitcookies')
+      return os.path.expanduser(os.path.join('~', '.gitcookies'))
 
   @classmethod
   def _get_gitcookies(cls):

tests/gerrit_util_test.py

@@ -123,7 +123,7 @@ class CookiesAuthenticatorTest(unittest.TestCase):
 
   def testGetGitcookiesPath(self):
     self.assertEqual(
-        os.path.join('$HOME', '.gitcookies'),
+        os.path.expanduser(os.path.join('~', '.gitcookies')),
         gerrit_util.CookiesAuthenticator().get_gitcookies_path())
 
     subprocess2.check_output.side_effect = ['http.cookiefile']

tests/git_cl_creds_check_report.txt

@@ -22,7 +22,7 @@
     chrome-internal.googlesource.com    git-example.chromium.org but google.com recommended
     chromium.googlesource.com           git-example.google.com but chromium.org recommended
 
-  You can manually remove corresponding lines in your ~/.gitcookies file and visit the following URLs with correct account to generate correct credential lines:
+  You can manually remove corresponding lines in your ~%(sep)s.gitcookies file and visit the following URLs with correct account to generate correct credential lines:
 
     https://chrome-internal-review.googlesource.com/new-password
     https://chromium-review.googlesource.com/new-password