new tool: download all GM images for a given builder, ready for skdiff

gm/rebaseline_server/results_test.py

 #!/usr/bin/python
 
 """
 Copyright 2013 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 Test results.py
 
@@ skipping 59 matching lines @@
   def test_gm(self):
     """Process results of a GM run with the Results object."""
     results_obj = results.Results(
         actuals_root=os.path.join(INPUT_DIR, 'gm-actuals'),
         expected_root=os.path.join(INPUT_DIR, 'gm-expectations'),
         generated_images_root=self._temp_dir)
     gm_json.WriteToFile(results_obj.get_results_of_type(results.RESULTS_ALL),
                         os.path.join(self._output_dir_actual, 'gm.json'))
 
 
+# TODO(epoger): create_empty_dir(), find_different_files(), etc. should be
+# extracted from this file to some common location, where they can be shared
+# with download_test.py and other users.
+
 def create_empty_dir(path):
   """Create an empty directory at the given path."""
   if os.path.isdir(path):
     shutil.rmtree(path)
   elif os.path.lexists(path):
     os.remove(path)
   os.makedirs(path)
 
 
 def find_different_files(dir1, dir2, ignore_subtree_names=None):
@@ skipping 24 matching lines @@
   return differing_files
 
 
 def main():
   suite = unittest.TestLoader().loadTestsFromTestCase(ResultsTest)
   unittest.TextTestRunner(verbosity=2).run(suite)
 
 
 if __name__ == '__main__':
   main()