Refactoring: Extract low-level git from push and merge scripts.

tools/push-to-trunk/auto_roll.py

 #!/usr/bin/env python
 # Copyright 2013 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
@@ skipping 75 matching lines @@
     self["tree_message"] = json.loads(status_json)["message"]
     if re.search(r"nopush|no push", self["tree_message"], flags=re.I):
       self.Die("Push to trunk disabled by tree state: %s"
                % self["tree_message"])
 
 
 class FetchLatestRevision(Step):
   MESSAGE = "Fetching latest V8 revision."
 
   def RunStep(self):
-    log = self.Git("svn log -1 --oneline").strip()
-    match = re.match(r"^r(\d+) ", log)
+    match = re.match(r"^r(\d+) ", self.GitSVNLog())
     if not match:
       self.Die("Could not extract current svn revision from log.")
     self["latest"] = match.group(1)
 
 
 class CheckLastPush(Step):
   MESSAGE = "Checking last V8 push to trunk."
 
   def RunStep(self):
     last_push_hash = self.FindLastTrunkPush()
-    last_push = int(self.Git("svn find-rev %s" % last_push_hash).strip())
+    last_push = int(self.GitSVNFindSVNRev(last_push_hash))
 
     # TODO(machenbach): This metric counts all revisions. It could be
     # improved by counting only the revisions on bleeding_edge.
     if int(self["latest"]) - last_push < 10:
       # This makes sure the script doesn't push twice in a row when the cron
       # job retries several times.
       self.Die("Last push too recently: %d" % last_push)
 
 
 class FetchLKGR(Step):
@@ skipping 85 matching lines @@
   parser = BuildOptions()
   (options, args) = parser.parse_args()
   if not options.a or not options.c or not options.reviewer:
     print "You need to specify author, chromium src location and reviewer."
     parser.print_help()
     return 1
   RunAutoRoll(CONFIG, AutoRollOptions(options))
 
 if __name__ == "__main__":
   sys.exit(Main())