svndiff.py: add ability to compare before-and-after JSON files, not just raw images

tools/rebaseline_imagefiles.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.
 '''
 
 '''
@@ skipping 59 matching lines @@
         self._expectations_root = expectations_root
         self._tests = tests
         self._configs = configs
         self._json_base_url = json_base_url
         self._json_filename = json_filename
         self._dry_run = dry_run
         self._add_new = add_new
         self._missing_json_is_fatal = missing_json_is_fatal
         self._googlestorage_gm_actuals_root = (
             'http://chromium-skia-gm.commondatastorage.googleapis.com/gm')
-        self._testname_pattern = re.compile('(\S+)_(\S+).png')
+        self._testname_pattern = re.compile(gm_json.IMAGE_FILENAME_PATTERN)
         self._is_svn_checkout = (
             os.path.exists(os.path.join(expectations_root, '.svn')) or
             os.path.exists(os.path.join(expectations_root, os.pardir, '.svn')))
         self._is_git_checkout = (
             os.path.exists(os.path.join(expectations_root, '.git')) or
             os.path.exists(os.path.join(expectations_root, os.pardir, '.git')))
 
     # If dry_run is False, execute subprocess.call(cmd).
     # If dry_run is True, print the command we would have otherwise run.
     # Raises a CommandFailedException if the command fails.
@@ skipping 185 matching lines @@
                 if config not in self._configs:
                     skipped_files.append(filename)
                     continue
             outfilename = os.path.join(self._expectations_root, subdir,
                                        filename);
             self._RebaselineOneFile(expectations_subdir=subdir,
                                     builder_name=builder,
                                     infilename=filename,
                                     outfilename=outfilename,
                                     all_results=all_results)