git-drover: TBR appropriate reviewers

When uploading to either Rietveld or Gerrit, this will
cause git-cl to add the appropriate reviewers to the
cherry-pick review, so they're aware the change is being
copied to the release branch.

When uploading to Gerrit, this will also cause git-cl to
set the Code-Review+1 bit, allowing the CL to be landed

R=tandrii@chromium.org

Bug: 714720
Change-Id: Ie04e2657a91e4345796ac2200c0115fb18e460a1
Reviewed-on: https://chromium-review.googlesource.com/486961
Commit-Queue: Aaron Gable <agable@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>

git_drover.py

@@ -9,6 +9,7 @@ import cPickle
 import functools
 import logging
 import os
+import re
 import shutil
 import subprocess
 import sys
@@ -274,7 +275,9 @@ class _Drover(object):
       return True
 
     self._run_git_command(['reset', '--hard'])
-    self._run_git_command(['cl', 'upload'],
+
+    author = self._run_git_command(['log', '-1', '--format=%ae']).strip()
+    self._run_git_command(['cl', 'upload', '--tbrs', author],
                           error_message='Upload failed',
                           interactive=True)
 
@@ -294,6 +297,9 @@ class _Drover(object):
           interaction. If false, the command will be provided with no input and
           the output is captured.
 
+    Returns:
+      stdout as a string, or stdout interleaved with stderr if self._verbose
+
     Raises:
       Error: The command failed to complete successfully.
     """
@@ -321,6 +327,9 @@ class _Drover(object):
       args: A list of strings containing the args to pass to git.
       stdin: A string to provide on stdin.
 
+    Returns:
+      stdout as a string, or stdout interleaved with stderr if self._verbose
+
     Raises:
       Error: The command failed to complete successfully.
     """

tests/git_drover_test.py

@@ -42,6 +42,7 @@ class GitDroverTest(auto_stub.TestCase):
     self._commands = []
     self._input = []
     self._fail_on_command = None
+    self._reviewers = ''
 
     self.REPO_CHECK_COMMANDS = [
         (['git', '--help'], self._parent_repo),
@@ -61,7 +62,9 @@ class GitDroverTest(auto_stub.TestCase):
     ]
     self.UPLOAD_COMMANDS = [
         (['git', 'reset', '--hard'], self._target_repo),
-        (['git', 'cl', 'upload'], self._target_repo),
+        (['git', 'log', '-1', '--format=%ae'], self._target_repo),
+        (['git', 'cl', 'upload', '--tbrs', 'author@domain.org'],
+         self._target_repo),
     ]
     self.LAND_COMMAND = [
         (['git', 'cl', 'land', '--bypass-hooks'], self._target_repo),
@@ -113,6 +116,8 @@ class GitDroverTest(auto_stub.TestCase):
       return os.path.join(self._parent_repo, '.git')
     if args == ['git', 'status', '--porcelain']:
       return ' D foo\nUU baz\n D bar\n'
+    if args == ['git', 'log', '-1', '--format=%ae']:
+      return 'author@domain.org'
     return ''
 
   def _Popen(self, args, shell=False, cwd=None, stdin=None, stdout=None,
@@ -293,7 +298,7 @@ class GitDroverTest(auto_stub.TestCase):
 
   def testFailOnUpload(self):
     self._input = ['y']
-    self._fail_on_command = 12
+    self._fail_on_command = 13
     self.assertRaises(git_drover.Error, git_drover.cherry_pick_change, 'branch',
                       'cl', self._parent_repo, False)
     self.assertEqual(self.REPO_CHECK_COMMANDS + self.LOCAL_REPO_COMMANDS +