rebaseline_server: allow user to specify which builders to process

gm/rebaseline_server/compare_rendered_pictures.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 results of two render_pictures runs.
 """
@@ skipping 79 matching lines @@
     Args:
       actuals_root: root directory containing all render_pictures-generated
           JSON files
       subdirs: (string, string) tuple; pair of subdirectories within
           actuals_root to compare
     """
     logging.info(
         'Reading actual-results JSON files from %s subdirs within %s...' % (
             subdirs, actuals_root))
     subdirA, subdirB = subdirs
-    subdirA_builder_dicts = results.BaseComparisons._read_dicts_from_root(
+    subdirA_builder_dicts = self._read_dicts_from_root(
         os.path.join(actuals_root, subdirA))
-    subdirB_builder_dicts = results.BaseComparisons._read_dicts_from_root(
+    subdirB_builder_dicts = self._read_dicts_from_root(
         os.path.join(actuals_root, subdirB))
     logging.info('Comparing subdirs %s and %s...' % (subdirA, subdirB))
 
     all_image_pairs = imagepairset.ImagePairSet(
         descriptions=subdirs,
         diff_base_url=self._diff_base_url)
     failing_image_pairs = imagepairset.ImagePairSet(
         descriptions=subdirs,
         diff_base_url=self._diff_base_url)
 
@@ skipping 86 matching lines @@
               'got exception while creating ImagePair for image_name '
               '"%s", builder "%s"' % (image_name, builder))
 
     self._results = {
       results.KEY__HEADER__RESULTS_ALL: all_image_pairs.as_dict(),
       results.KEY__HEADER__RESULTS_FAILURES: failing_image_pairs.as_dict(),
     }
 
 
 # TODO(epoger): Add main() so this can be called by vm_run_skia_try.sh