Introduce --send-email flag as an alias to --send-mail for `git cl upload`

Vanilla git has a git-send-email(1) subcommand. `git cl upload` should
follow suit by using the same flag name to be consistent and avoid
confusion.

[1]: https://git-scm.com/docs/git-send-email

Bug: none
Change-Id: I47ff8e03bd11915e99804fe1695046d874efc4e0
Tested: `git cl upload --send-email` to upload this very own CL
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3854330
Reviewed-by: Aravind Vasudevan <aravindvasudev@google.com>
Commit-Queue: Aravind Vasudevan <aravindvasudev@google.com>
Auto-Submit: Thiago Perrotta <tperrotta@chromium.org>

git_cl.py

@@ -2508,8 +2508,8 @@ class Changelist(object):
     refspec_opts = []
 
     # By default, new changes are started in WIP mode, and subsequent patchsets
-    # don't send email. At any time, passing --send-mail will mark the change
-    # ready and send email for that particular patch.
+    # don't send email. At any time, passing --send-mail or --send-email will
+    # mark the change ready and send email for that particular patch.
     if options.send_mail:
       refspec_opts.append('ready')
       refspec_opts.append('notify=ALL')
@@ -2518,8 +2518,9 @@ class Changelist(object):
     else:
       refspec_opts.append('notify=NONE')
 
-    # TODO(tandrii): options.message should be posted as a comment
-    # if --send-mail is set on non-initial upload as Rietveld used to do it.
+    # TODO(tandrii): options.message should be posted as a comment if
+    # --send-mail or --send-email is set on non-initial upload as Rietveld used
+    # to do it.
 
     # Set options.title in case user was prompted in _GetTitleForUpload and
     # _CMDUploadChange needs to be called again.
@@ -2609,11 +2610,11 @@ class Changelist(object):
     if self.GetIssue() and (reviewers or cc):
       # GetIssue() is not set in case of non-squash uploads according to tests.
       # TODO(crbug.com/751901): non-squash uploads in git cl should be removed.
-      gerrit_util.AddReviewers(
-          self.GetGerritHost(),
-          self._GerritChangeIdentifier(),
-          reviewers, cc,
-          notify=bool(options.send_mail))
+      gerrit_util.AddReviewers(self.GetGerritHost(),
+                               self._GerritChangeIdentifier(),
+                               reviewers,
+                               cc,
+                               notify=bool(options.send_mail))
 
     return 0
 
@@ -4313,7 +4314,11 @@ def CMDupload(parser, args):
                     action='append', default=[],
                     help=('Gerrit hashtag for new CL; '
                           'can be applied multiple times'))
-  parser.add_option('-s', '--send-mail', action='store_true',
+  parser.add_option('-s',
+                    '--send-mail',
+                    '--send-email',
+                    dest='send_mail',
+                    action='store_true',
                     help='send email to reviewer(s) and cc(s) immediately')
   parser.add_option('--target_branch',
                     '--target-branch',
@@ -4330,10 +4335,12 @@ def CMDupload(parser, args):
                     const='TBR', help='add a set of OWNERS to TBR')
   parser.add_option('--r-owners', dest='add_owners_to', action='store_const',
                     const='R', help='add a set of OWNERS to R')
-  parser.add_option('-c', '--use-commit-queue', action='store_true',
+  parser.add_option('-c',
+                    '--use-commit-queue',
+                    action='store_true',
                     default=False,
                     help='tell the CQ to commit this patchset; '
-                         'implies --send-mail')
+                    'implies --send-mail')
   parser.add_option('-d', '--cq-dry-run',
                     action='store_true', default=False,
                     help='Send the patchset to do a CQ dry run right after '

tests/git_cl_test.py

@@ -1315,6 +1315,18 @@ class TestGitCl(unittest.TestCase):
         final_description=(
             'desc ✔\n\nBUG=\nR=foo@example.com\n\nChange-Id: I123456789'))
 
+  def test_gerrit_reviewers_cmd_line_send_email(self):
+    self._run_gerrit_upload_test(
+        ['-r', 'foo@example.com', '--send-email'],
+        'desc ✔\n\nBUG=\n\nChange-Id: I123456789',
+        reviewers=['foo@example.com'],
+        squash=False,
+        squash_mode='override_nosquash',
+        notify=True,
+        change_id='I123456789',
+        final_description=(
+            'desc ✔\n\nBUG=\nR=foo@example.com\n\nChange-Id: I123456789'))
+
   def test_gerrit_upload_force_sets_bug(self):
     self._run_gerrit_upload_test(
         ['-b', '10000', '-f'],