Correctly overwrite author in chromium roll script.

tools/push-to-trunk/chromium_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 os
 import sys
 
 from common_includes import *
@@ skipping 68 matching lines @@
     if self._side_effect_handler.Command(
         "roll-dep", "v8 %s" % self["trunk_revision"]) is None:
       self.Die("Failed to create deps for %s" % self["trunk_revision"])
 
     commit_title = "Update V8 to %s." % self["push_title"].lower()
     sheriff = ""
     if self["sheriff"]:
       sheriff = ("\n\nPlease reply to the V8 sheriff %s in case of problems."
                  % self["sheriff"])
     self.GitCommit("%s%s\n\nTBR=%s" %
-                   (commit_title, sheriff, self._options.reviewer))
+                       (commit_title, sheriff, self._options.reviewer),
+                   author=self._options.author)
     if not self._options.dry_run:
       self.GitUpload(author=self._options.author,
                      force=True,
                      cq=self._options.use_commit_queue)
       print "CL uploaded."
     else:
       self.GitCheckout("master")
       self.GitDeleteBranch("v8-roll-%s" % self["trunk_revision"])
       print "Dry run - don't upload."
 
@@ skipping 46 matching lines @@
       SwitchChromium,
       UpdateChromiumCheckout,
       UploadCL,
       SwitchV8,
       CleanUp,
     ]
 
 
 if __name__ == "__main__":  # pragma: no cover
   sys.exit(ChromiumRoll(CONFIG).Run())