tryserver recipe_module: Add get_tags.

recipe_modules/tryserver/example.py

Index: recipe_modules/tryserver/example.py
diff --git a/recipe_modules/tryserver/example.py b/recipe_modules/tryserver/example.py
index dead670bf8d44eb3cefc5370f3b6766092d7272d..713341f5264365f3a4281f15abecd773ba2c58b0 100644
--- a/recipe_modules/tryserver/example.py
+++ b/recipe_modules/tryserver/example.py
@@ -3,17 +3,25 @@
 # found in the LICENSE file.
 
 DEPS = [
+  'recipe_engine/raw_io',
   'recipe_engine/path',
   'recipe_engine/platform',
   'recipe_engine/properties',
   'recipe_engine/python',
+  'recipe_engine/step',
   'tryserver',
 ]
 
 
 def RunSteps(api):
+  if api.properties.get('patch_text'):
+    api.step('patch_text test', [
+        'echo', str(api.tryserver.get_tags(api.properties['patch_text']))])
+    return
+
   api.path['checkout'] = api.path['slave_build']
   api.tryserver.maybe_apply_issue()
+  api.tryserver.get_tags()
   api.tryserver.get_files_affected_by_patch()
 
   if api.tryserver.is_tryserver:
@@ -29,17 +37,28 @@ def RunSteps(api):
 
 
 def GenTests(api):
+  description_step = api.override_step_data(
+      'Get description', api.raw_io.output("foobar"))
   yield (api.test('with_svn_patch') +
-         api.properties(patch_url='svn://checkout.url'))
+         api.properties(patch_url='svn://checkout.url') +
+         description_step)
 
   yield (api.test('with_git_patch') +
          api.properties(
               patch_storage='git',
               patch_project='v8',
               patch_repo_url='http://patch.url/',
-              patch_ref='johndoe#123.diff'))
+              patch_ref='johndoe#123.diff') +
+         description_step)
 
   yield (api.test('with_rietveld_patch') +
-         api.properties.tryserver())
+         api.properties.tryserver() +
+         description_step)
+
+  yield (api.test('with_wrong_patch') + api.platform('win', 32) +
+         description_step)
 
-  yield (api.test('with_wrong_patch') + api.platform('win', 32))
+  yield (api.test('basic_tags') +
+         api.properties(
+             patch_text="hihihi\nfoo=bar")
+         )