Add ability to output ImageBaseGSUrl to render_picture and use in rebaseline server

gm/rebaseline_server/compare_configs.py

 #!/usr/bin/python
 
 """
 Copyright 2014 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 Compare GM results for two configs, across all builders.
 """
@@ skipping 133 matching lines @@
                 results.KEY__EXTRACOLUMNS__TEST: test,
                 # TODO(epoger): Right now, the client UI crashes if it receives
                 # results that do not include a 'config' column.
                 # Until we fix that, keep the client happy.
                 results.KEY__EXTRACOLUMNS__CONFIG: 'TODO',
             }
 
             try:
               image_pair = imagepair.ImagePair(
                   image_diff_db=self._image_diff_db,
-                  base_url=gm_json.GM_ACTUALS_ROOT_HTTP_URL,
+                  imageA_base_url=gm_json.GM_ACTUALS_ROOT_HTTP_URL,
+                  imageB_base_url=gm_json.GM_ACTUALS_ROOT_HTTP_URL,
                   imageA_relative_url=configA_image_relative_url,
                   imageB_relative_url=configB_image_relative_url,
                   extra_columns=extra_columns_dict)
               all_image_pairs.add_image_pair(image_pair)
               if result_type != results.KEY__RESULT_TYPE__SUCCEEDED:
                 failing_image_pairs.add_image_pair(image_pair)
             except (KeyError, TypeError):
               logging.exception(
                   'got exception while creating ImagePair for test '
                   '"%s", builder "%s"' % (test, builder))
@@ skipping 34 matching lines @@
   results_obj = ConfigComparisons(configs=args.config,
                                   actuals_root=args.actuals,
                                   generated_images_root=args.workdir)
   gm_json.WriteToFile(
       results_obj.get_packaged_results_of_type(results_type=args.results),
       args.outfile)
 
 
 if __name__ == '__main__':
   main()