Fix new git workflow in release scripts.

tools/push-to-trunk/common_includes.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 352 matching lines @@
     self.step.Git("rebase %s" % remote)
     self.step.GitSVNTag(tag)
 
 
 class GitTagsOnlyMixin(VCInterface):
   def Pull(self):
     self.step.GitPull()
 
   def Fetch(self):
     self.step.Git("fetch")
+    self.step.GitSVNFetch()
 
   def GetTags(self):
      return self.step.Git("tag").strip().splitlines()
 
   def GetBranches(self):
     # Get relevant remote branches, e.g. "branch-heads/3.25".
     branches = filter(
         lambda s: re.match(r"^branch\-heads/\d+\.\d+$", s),
         self.step.GitRemotes())
     # Remove 'branch-heads/' prefix.
@@ skipping 500 matching lines @@
     for (number, step_class) in enumerate(step_classes):
       steps.append(MakeStep(step_class, number, self._state, self._config,
                             options, self._side_effect_handler))
     for step in steps[options.step:]:
       if step.Run():
         return 0
     return 0
 
   def Run(self, args=None):
     return self.RunSteps(self._Steps(), args)