Add automatic retry mechanism and LKGR support.

projects.py

Index: projects.py
diff --git a/projects.py b/projects.py
index 9719bfab2a3b41e86c19808abee21b78e57184c7..d254abffecb03a188867d9d8c8ec1e594b561564 100644
--- a/projects.py
+++ b/projects.py
@@ -6,6 +6,7 @@
 import os
 import re
 import sys
+import urllib2
 
 import find_depot_tools  # pylint: disable=W0611
 import checkout
@@ -53,6 +54,13 @@ def _get_escaped_committers(root_dir):
   return [re.escape(i) for i in committer_list.get_committers(password)]
 
 
+def _chromium_lkgr():
+  try:
+    return int(
+        urllib2.urlopen('http://chromium-status.appspot.com/lkgr').read())
+  except (ValueError, IOError):
+    return None
+
 def _gen_chromium(user, root_dir, rietveld_obj, no_try):
   """Generates a PendingManager commit queue for chrome/trunk/src."""
   svn_creds = creds.Credentials(os.path.join(root_dir, '.svn_pwd'))
@@ -93,7 +101,8 @@ def _gen_chromium(user, root_dir, rietveld_obj, no_try):
         user,
         builders,
         tests,
-        ['--root', 'src']))
+        ['--root', 'src'],
+        _chromium_lkgr))
 
   verifiers.append(tree_status.TreeStatusVerifier(
       'http://chromium-status.appspot.com/status'))