Make auto_roll run with a pure git checkout.

tools/push-to-trunk/auto_roll.py

 #!/usr/bin/env python
 # Copyright 2014 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import argparse
 import json
 import os
 import sys
 import urllib
@@ skipping 32 matching lines @@
     result = self.ReadURL(search_url, params, wait_plan=[5, 20])
     if self.ContainsChromiumRoll(json.loads(result)["results"]):
       print "Stop due to existing Chromium roll."
       return True
 
 
 class DetectLastPush(Step):
   MESSAGE = "Detect commit ID of the last push to trunk."
 
   def RunStep(self):
-    push_hash = self.FindLastTrunkPush(include_patches=True)
-    self["last_push"] = self.GitSVNFindSVNRev(push_hash)
+    push_hash = self.FindLastTrunkPush(
+        branch="origin/master", include_patches=True)
+    self["last_push"] = self.GetCommitPositionNumber(push_hash)
 
 
 class DetectLastRoll(Step):
   MESSAGE = "Detect commit ID of the last Chromium roll."
 
   def RunStep(self):
     # Interpret the DEPS file to retrieve the v8 revision.
     Var = lambda var: '%s'
     exec(self.ReadURL(CR_DEPS_URL))
     last_roll = vars['v8_revision']
-    if last_roll >= self["last_push"]:
+    # FIXME(machenbach): When rolling from bleeding edge and from trunk there
+    # be different commit numbers here. Better use version?
+    if int(last_roll) >= int(self["last_push"]):
       print("There is no newer v8 revision than the one in Chromium (%s)."
             % last_roll)
       return True
 
 
 class CheckClusterFuzz(Step):
   MESSAGE = "Check ClusterFuzz api for new problems."
 
   def RunStep(self):
     if not os.path.exists(self.Config(CLUSTERFUZZ_API_KEY_FILE)):
@@ skipping 54 matching lines @@
       CheckActiveRoll,
       DetectLastPush,
       DetectLastRoll,
       CheckClusterFuzz,
       RollChromium,
     ]
 
 
 if __name__ == "__main__":  # pragma: no cover
   sys.exit(AutoRoll(CONFIG).Run())