Revert of Stop prepending "r" to commit hashes in merge_to_branch.py

tools/release/merge_to_branch.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 86 matching lines @@
                       % ", ".join(port_revision_list)):
         #: 'y': Add ports to revision list.
         self["full_revision_list"].extend(port_revision_list)
 
 
 class CreateCommitMessage(Step):
   MESSAGE = "Create commit message."
 
   def RunStep(self):
 
-    # Stringify: ["abcde", "12345"] -> "abcde, 12345"
-    self["revision_list"] = ", ".join(self["full_revision_list"]))
+    # Stringify: [123, 234] -> "r123, r234"
+    self["revision_list"] = ", ".join(map(lambda s: "r%s" % s,
+                                      self["full_revision_list"]))
 
     if not self["revision_list"]:  # pragma: no cover
       self.Die("Revision list is empty.")
 
     if self._options.revert and not self._options.revert_master:
       action_text = "Rollback of %s"
     else:
       action_text = "Merged %s"
 
     # The commit message title is added below after the version is specified.
@@ skipping 187 matching lines @@
       CommitLocal,
       UploadStep,
       CommitRepository,
       TagRevision,
       CleanUp,
     ]
 
 
 if __name__ == "__main__":  # pragma: no cover
   sys.exit(MergeToBranch().Run())