Remove unused function _invert_dictionary from baseline_optimizer.py.

third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baseline_optimizer.py

 # Copyright (C) 2011, Google Inc. 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 disclaimer
@@ skipping 17 matching lines @@
 
 import copy
 import logging
 import functools
 
 from webkitpy.common.memoized import memoized
 
 _log = logging.getLogger(__name__)
 
 
-# FIXME: Should this function be somewhere more general?
-def _invert_dictionary(dictionary):
-    inverted_dictionary = {}
-    for key, value in dictionary.items():
-        if inverted_dictionary.get(value):
-            inverted_dictionary[value].append(key)
-        else:
-            inverted_dictionary[value] = [key]
-    return inverted_dictionary
-
-
 class BaselineOptimizer(object):
     ROOT_LAYOUT_TESTS_DIRECTORY = 'LayoutTests'
 
     def __init__(self, host, port, port_names):
         self._filesystem = host.filesystem
         self._default_port = port
         self._ports = {}
         for port_name in port_names:
             self._ports[port_name] = host.port_factory.get(port_name)
 
@@ skipping 260 matching lines @@
         result = self._optimize_subtree(baseline_name)
         non_virtual_baseline_name = self._virtual_base(baseline_name)
         if not non_virtual_baseline_name:
             return result
 
         self._optimize_virtual_root(baseline_name, non_virtual_baseline_name)
 
         _log.debug("Optimizing non-virtual fallback path.")
         result |= self._optimize_subtree(non_virtual_baseline_name)
         return result