Keep svn checkout up-to-date in roll 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 514 matching lines @@
       elif line.startswith("#define BUILD_NUMBER"):
         line = re.sub("\d+$", self[prefix + "build"], line)
       elif line.startswith("#define PATCH_LEVEL"):
         line = re.sub("\d+$", self[prefix + "patch"], line)
       output += "%s\n" % line
     TextToFile(output, version_file)
 
   def SVNCommit(self, root, commit_message):
     patch = self.GitDiff("HEAD^", "HEAD")
     TextToFile(patch, self._config[PATCH_FILE])
+    self.Command("svn", "update", cwd=self._options.svn)
+    if self.Command("svn", "status", cwd=self._options.svn) != "":
+      self.Die("SVN checkout not clean.")
     if not self.Command("patch", "-d %s -p1 -i %s" %
                         (root, self._config[PATCH_FILE]),
                         cwd=self._options.svn):
       self.Die("Could not apply patch.")
     self.Command(
         "svn",
         "commit --non-interactive --username=%s --config-dir=%s -m \"%s\"" %
             (self._options.author, self._options.svn_config, commit_message),
         cwd=self._options.svn)
 
@@ skipping 158 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)