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

tools/rebaseline.py

Index: tools/rebaseline.py
===================================================================
--- tools/rebaseline.py	(revision 10108)
+++ tools/rebaseline.py	(working copy)
@@ -101,7 +101,7 @@
         self._actuals_base_url = actuals_base_url
         self._actuals_filename = actuals_filename
         self._add_new = add_new
-        self._testname_pattern = re.compile('(\S+)_(\S+).png')
+        self._image_filename_re = re.compile(gm_json.IMAGE_FILENAME_PATTERN)
 
     # Returns the full contents of filepath, as a single string.
     # If filepath looks like a URL, try to read it that way instead of as
@@ -185,7 +185,7 @@
         skipped_images = []
         if results_to_update:
             for (image_name, image_results) in results_to_update.iteritems():
-                (test, config) = self._testname_pattern.match(image_name).groups()
+                (test, config) = self._image_filename_re.match(image_name).groups()

[borenet, 2013/07/16 18:31:03]

nit: 80 chars

Also, why are we using four space indents in this file?

[epoger, 2013/07/16 18:42:32]

Thanks to Python's whitespace-sensitivity, I couldn't think of a way to break
this line that would work.  Can you?
I guess because my emacs configuration was doing that by default.

If it's OK with you, I would like to commit this CL as-is and fix the spacing
separately.  I have added TODOs in each of these files that are 4-space
indented.

[borenet, 2013/07/16 18:48:37]

It's ugly, but what about:
(test, config) = \
    self._image_filename_re.match(image_name).groups()
?
SGTM

                 if self._tests:
                     if test not in self._tests:
                         skipped_images.append(image_name)