Rolling forward https://codereview.chromium.org/1155683008/ which was

third_party/closure_compiler/compiler_test.py

 #!/usr/bin/env python
 # Copyright 2014 The Chromium 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 os
 import tempfile
 import unittest
 
 from compile import Checker
 from processor import FileCache, Processor
 
 
 _SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 _SRC_DIR = os.path.join(_SCRIPT_DIR, os.pardir, os.pardir)
 _RESOURCES_DIR = os.path.join(_SRC_DIR, "ui", "webui", "resources", "js")
 _ASSERT_JS = os.path.join(_RESOURCES_DIR, "assert.js")
 _CR_JS = os.path.join(_RESOURCES_DIR, "cr.js")
 _CR_UI_JS = os.path.join(_RESOURCES_DIR, "cr", "ui.js")
-_POLYMER_EXTERNS = os.path.join(_SRC_DIR, "third_party", "polymer", "v0_8",
+_POLYMER_EXTERNS = os.path.join(_SRC_DIR, "third_party", "polymer", "v1_0",
                                 "components-chromium", "polymer-externs",
                                 "polymer.externs.js")
 
 
 class CompilerTest(unittest.TestCase):
   _ASSERT_DEFINITION = Processor(_ASSERT_JS).contents
   _CR_DEFINE_DEFINITION = Processor(_CR_JS).contents
   _CR_UI_DECORATE_DEFINITION = Processor(_CR_UI_JS).contents
 
   def setUp(self):
@@ skipping 285 matching lines @@
 
     expected_output = "'use strict';var testScript=function(){};testScript();\n"
     self.assertTrue(os.path.exists(out_map))
     self.assertTrue(os.path.exists(out_file))
     with open(out_file, "r") as file:
       self.assertEquals(file.read(), expected_output)
 
 
 if __name__ == "__main__":
   unittest.main()