Fix chromium update in chromium roll script.

tools/push-to-trunk/test_scripts.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 842 matching lines @@
       Cmd("git svn fetch", ""),
       Cmd(("git log -1 --format=%H --grep="
            "\"^Version [[:digit:]]*\.[[:digit:]]*\.[[:digit:]]*\" "
            "svn/trunk"), "push_hash\n"),
       Cmd("git svn find-rev push_hash", "123455\n"),
       Cmd("git log -1 --format=%s push_hash",
           "Version 3.22.5 (based on bleeding_edge revision r123454)\n"),
       Cmd("git status -s -uno", ""),
       Cmd("git checkout -f master", ""),
       Cmd("gclient sync --nohooks", "syncing..."),
+      Cmd("git pull", ""),
       Cmd("git fetch origin", ""),
       Cmd("git checkout -b v8-roll-123455", ""),
       Cmd("roll-dep v8 123455", "rolled", cb=WriteDeps),
       Cmd(("git commit -am \"Update V8 to version 3.22.5 "
            "(based on bleeding_edge revision r123454).\n\n"
            "Please reply to the V8 sheriff c_name@chromium.org in "
            "case of problems.\n\nTBR=c_name@chromium.org\""),
           ""),
       Cmd(("git cl upload --send-mail --email \"author@chromium.org\"%s"
            % force_flag), ""),
@@ skipping 670 matching lines @@
 
 Review URL: https://codereview.chromium.org/83173002
 
 ------------------------------------------------------------------------""")
     self.assertEquals(
 """Prepare push to trunk.  Now working on version 3.23.11.
 
 R=danno@chromium.org
 
 Committed: https://code.google.com/p/v8/source/detail?r=17997""", body)