Improve branch creation in release scripts.

tools/push-to-trunk/git_recipes.py

 #!/usr/bin/env python
 # Copyright 2014 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 87 matching lines @@
 
 
 class GitRecipesMixin(object):
   def GitIsWorkdirClean(self, **kwargs):
     return self.Git("status -s -uno", **kwargs).strip() == ""
 
   @Strip
   def GitBranch(self, **kwargs):
     return self.Git("branch", **kwargs)
 
-  def GitCreateBranch(self, name, branch="", **kwargs):
+  def GitCreateBranch(self, name, remote="", **kwargs):
     assert name
-    self.Git(MakeArgs(["checkout -b", name, branch]), **kwargs)
+    remote_args = ["--upstream", remote] if remote else []
+    self.Git(MakeArgs(["new-branch", name] + remote_args), **kwargs)
 
   def GitDeleteBranch(self, name, **kwargs):
     assert name
     self.Git(MakeArgs(["branch -D", name]), **kwargs)
 
   def GitReset(self, name, **kwargs):
     assert name
     self.Git(MakeArgs(["reset --hard", name]), **kwargs)
 
   def GitStash(self, **kwargs):
@@ skipping 188 matching lines @@
   def GitSVNFindSVNRev(self, git_hash, branch="", **kwargs):
     return self.Git(MakeArgs(["svn find-rev", git_hash, branch]), **kwargs)
 
   def GitSVNDCommit(self, **kwargs):
     return self.Git("svn dcommit 2>&1", retry_on=lambda x: x is None, **kwargs)
 
   def GitSVNTag(self, version, **kwargs):
     self.Git(("svn tag %s -m \"Tagging version %s\"" % (version, version)),
              retry_on=lambda x: x is None,
              **kwargs)