build: add recipe code for new autoroller

scripts/slave/recipe_modules/recipe_autoroller/test_api.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 import recipe_test_api
+
+
+class RecipeAutorollerTestApi(recipe_test_api.RecipeTestApi):
+  def roll_data(self, project, success=True, trivial=True, empty=False):
+    """Returns mock roll data for |project|."""
+    if empty:
+      success = False
+
+    ret = self.empty_test_data()
+
+    picked_roll_details = {
+      'commit_infos': {
+        'recipe_engine': [
+          {
+            'author': 'foo@chromium.org',
+            'message': 'some commit message',
+            'revision': '123abc',
+          },
+        ],
+      },
+    }
+
+    roll_result = {
+      'success': success,
+      'trivial': trivial if success else None,
+      'picked_roll_details': picked_roll_details if success else None,
+      'rejected_candidates_details': [],
+    }
+    if empty:
+      roll_result['roll_details'] = []
+    else:
+      roll_result['roll_details'] = [picked_roll_details]
+      if not success:
+        roll_result['rejected_candidates_details'].append({
+          'spec': 'some_spec',
+          'commit_infos': {
+          },
+        })
+
+    ret += self.step_data('%s.roll' % project, self.m.json.output(roll_result))
+    return ret