Add colors to git cl comments.

tests/git_cl_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for git_cl.py."""
 
 import os
 import StringIO
 import stat
@@ skipping 437 matching lines @@
     description = 'Foo Bar\nR=reviewer@example.com'
     self._run_reviewer_test(
         ['--send-mail'],
         'desc\n\nBUG=',
         description.strip('\n'),
         description,
         ['--reviewers=reviewer@example.com', '--send_mail'])
 
   def test_reviewer_send_mail_no_rev(self):
     # Fails without a reviewer.
-    class FileMock(object):
-      buf = StringIO.StringIO()
-      def write(self, content):
-        self.buf.write(content)
-
-    mock = FileMock()
+    stdout = StringIO.StringIO()
+    stderr = StringIO.StringIO()
     try:
       self.calls = self._upload_no_rev_calls(None, None)
       def RunEditor(desc, _, **kwargs):
         return desc
       self.mock(git_cl.gclient_utils, 'RunEditor', RunEditor)
-      self.mock(sys, 'stderr', mock)
+      self.mock(sys, 'stdout', stdout)
+      self.mock(sys, 'stderr', stderr)
       git_cl.main(['upload', '--send-mail'])
       self.fail()
     except SystemExit:
-      self.assertEquals(
-          'Must specify reviewers to send email.\n', mock.buf.getvalue())
+      self.assertEqual(
+          'Using 50% similarity for rename/copy detection. Override with '
+          '--similarity.\n',
+          stdout.getvalue())
+      self.assertEqual(
+          'Must specify reviewers to send email.\n', stderr.getvalue())
 
   def test_dcommit(self):
     self.calls = (
         self._dcommit_calls_1() +
         self._git_sanity_checks('fake_ancestor_sha', 'working') +
         self._dcommit_calls_normal() +
         self._dcommit_calls_3())
     git_cl.main(['dcommit'])
 
   def test_dcommit_bypass_hooks(self):
@@ skipping 200 matching lines @@
       obj = git_cl.ChangeDescription(orig)
       obj.update_reviewers(reviewers)
       actual.append(obj.description)
     self.assertEqual(expected, actual)
 
 
 if __name__ == '__main__':
   git_cl.logging.basicConfig(
       level=git_cl.logging.DEBUG if '-v' in sys.argv else git_cl.logging.ERROR)
   unittest.main()