rebaseline_server: force checksumValue to an integer to prevent spurious comparison failures

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 381 matching lines @@
     Returns:
       An ImagePair object, or None if both image_dict_A and image_dict_B are
       None.
     """
     if (not image_dict_A) and (not image_dict_B):
       return None
 
     def _checksum_and_relative_url(dic):
       if dic:
         return ((dic[gm_json.JSONKEY_IMAGE_CHECKSUMALGORITHM],
-                 dic[gm_json.JSONKEY_IMAGE_CHECKSUMVALUE]),
+                 int(dic[gm_json.JSONKEY_IMAGE_CHECKSUMVALUE])),
                 dic[gm_json.JSONKEY_IMAGE_FILEPATH])
       else:
         return None, None
 
     imageA_checksum, imageA_relative_url = _checksum_and_relative_url(
         image_dict_A)
     imageB_checksum, imageB_relative_url = _checksum_and_relative_url(
         image_dict_B)
 
     if not imageA_checksum:
@@ skipping 66 matching lines @@
       source_dir: path to source dir (GS URL, local filepath, or a special
           "repo:" URL type that points at a file within our Skia checkout;
           only the "repo:" URL type will have a commit hash.
     """
     if source_dir.lower().startswith(REPO_URL_PREFIX):
       repo_dir = os.path.join(REPO_BASEPATH, source_dir[len(REPO_URL_PREFIX):])
       return subprocess.check_output(
           args=[git_utils.GIT, 'rev-parse', 'HEAD'], cwd=repo_dir).strip()
     else:
       return None