Add recipe for testing recipe simulation.

scripts/slave/recipes/infra/recipe_simulation.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.
+"""A continious builder for build repo which simulates recipes."""
+
+DEPS = [
+  'bot_update',
+  'gclient',
+  'recipe_engine/path',
+  'recipe_engine/properties',
+  'recipe_engine/step',
+]
+
+
+def RunSteps(api):
+  api.gclient.set_config('build')

[Michael Achenbach, 2016/01/11 14:56:25]

Suggestion: You could also force bot_update to use whatever was set as revision
property (not sure if it already does that by default). Like that one can use
forced rerun with particular revisions through the ui.

[tandrii(chromium), 2016/01/11 15:21:35]

I have no idea how to do thaat, but I like this idea.

+  step = api.bot_update.ensure_checkout(force=True, patch_root='build')
+  recipes_py = api.path['checkout'].join('scripts', 'slave', 'recipes.py')
+  api.step('recipe fetch deps', [recipes_py, 'fetch'])

[tandrii(chromium), 2016/01/11 14:46:42]

technically, step below fetches automatically, but I don't want next step to
fail on network.

+  api.step('recipe simulation test', [recipes_py, 'simulation_test'])
+
+
+def GenTests(api):
+  yield (
+      api.test('normal') +
+      api.properties.generic(
+          mastername='chromium.tools.build',
+          buildername='recipe simulation tester',
+          revision_tag='deadbeaf',

[Michael Achenbach, 2016/01/11 14:54:59]

Should this not just be revision?

[tandrii(chromium), 2016/01/11 15:21:35]

oops, copy-pasta. I don't think I even need it.

+      )
+  )