Add extracting GM comments to the housekeeper bot.

infra/bots/recipes/swarm_housekeeper.py

Index: infra/bots/recipes/swarm_housekeeper.py
diff --git a/infra/bots/recipes/swarm_housekeeper.py b/infra/bots/recipes/swarm_housekeeper.py
index ae31611b1e673454a705cc0950020c79c6e4332c..43e694c3843e8069ac5f3956795cd63365081f56 100644
--- a/infra/bots/recipes/swarm_housekeeper.py
+++ b/infra/bots/recipes/swarm_housekeeper.py
@@ -5,7 +5,6 @@
 
 # Recipe for the Skia PerCommit Housekeeper.
 
-
 DEPS = [
   'core',
   'recipe_engine/path',
@@ -68,6 +67,30 @@ def RunSteps(api):
     cwd=cwd,
     abort_on_failure=False)
 
+  env = {}
+  env['GOPATH'] = api.vars.tmp_dir.join('golib')
+  extractexe = env['GOPATH'].join('bin', 'extract_comments')
+  goexe = api.vars.slave_dir.join('go', 'go', 'bin', 'go')
+
+  # Compile extract_comments.
+  api.run(
+    api.step,
+    'compile extract_comments',
+    cmd=[goexe, 'get', 'go.skia.org/infra/comments/go/extract_comments'],
+    cwd=cwd,
+    env=env,
+    abort_on_failure=True)
+
+  # Run extract_comments on the gm directory.
+  api.run(
+    api.step,
+    'run extract_comments',
+    cmd=[extractexe, '--dir', 'gm', '--dest', 'gs://skia-doc/gm/comments.json'],
+    cwd=cwd,
+    env=env,
+    abort_on_failure=True)
+
+
 def GenTests(api):
   for mastername, slaves in TEST_BUILDERS.iteritems():
     for slavename, builders_by_slave in slaves.iteritems():