Add git_cl recipe module.

recipe_modules/git_cl/example.py

+# Copyright 2016 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.
+
+from recipe_engine.config_types import Path
+
+
+DEPS = [
+  'git_cl',
+  'recipe_engine/path',
+  'recipe_engine/raw_io',
+  'recipe_engine/step',
+]
+
+
+def RunSteps(api):
+  res = api.git_cl.get_description(cwd=api.path.mkdtemp('fakee'))
+  # Look ma, no hands! (Can pass in the cwd without configuring git_cl).
+  api.step('echo', ['echo', res.stdout])
+
+  api.git_cl.set_config('basic')
+  api.git_cl.c.repo_location = api.path.mkdtemp('fakerepo')
+
+  api.step('echo', ['echo', api.git_cl.get_description().stdout])
+
+  api.git_cl.set_description("new description woo")
+
+  api.step('echo', ['echo', api.git_cl.get_description().stdout])
+
+def GenTests(api):
+  yield (
+      api.test('basic') +
+      api.override_step_data(
+          'git_cl description', stdout=api.raw_io.output('hi')) +
+      api.override_step_data(
+          'git_cl description (2)', stdout=api.raw_io.output('hey')) +
+      api.override_step_data(
+          'git_cl description (3)', stdout=api.raw_io.output(
+              'new description woo'))
+  )
+