teach rebaseline_server to generate diffs of rendered SKPs

gm/rebaseline_server/compare_rendered_pictures_test.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.
 
 Test compare_rendered_pictures.py
 
@@ skipping 12 matching lines @@
 import subprocess
 
 # Must fix up PYTHONPATH before importing from within Skia
 import fix_pythonpath  # pylint: disable=W0611
 
 # Imports from within Skia
 import base_unittest
 import compare_rendered_pictures
 import find_run_binary
 import gm_json
+import imagediffdb
 import results
 
 
 class CompareRenderedPicturesTest(base_unittest.TestCase):
 
   def test_endToEnd(self):
     """Generate two sets of SKPs, run render_pictures over both, and compare
     the results."""
+    actuals_label = 'before_patch'
+    expectations_label = 'after_patch'
     self._generate_skps_and_run_render_pictures(
-        subdir='before_patch', skpdict={
+        subdir=actuals_label, skpdict={
             'changed.skp': 200,
             'unchanged.skp': 100,
             'only-in-before.skp': 128,
         })
     self._generate_skps_and_run_render_pictures(
-        subdir='after_patch', skpdict={
+        subdir=expectations_label, skpdict={
             'changed.skp': 201,
             'unchanged.skp': 100,
             'only-in-after.skp': 128,
         })
 
     results_obj = compare_rendered_pictures.RenderedPicturesComparisons(
-        actuals_root=self.temp_dir,
-        subdirs=('before_patch', 'after_patch'),
-        generated_images_root=self.temp_dir,
-        diff_base_url='/static/generated-images')
+        actuals_dirs=[os.path.join(self.temp_dir, actuals_label)],
+        expectations_dirs=[os.path.join(self.temp_dir, expectations_label)],
+        image_diff_db=imagediffdb.ImageDiffDB(self.temp_dir),
+        image_base_gs_url='gs://fakebucket/fake/path',
+        diff_base_url='/static/generated-images',
+        actuals_label=actuals_label, expectations_label=expectations_label)
     results_obj.get_timestamp = mock_get_timestamp
 
     gm_json.WriteToFile(
         results_obj.get_packaged_results_of_type(
             results.KEY__HEADER__RESULTS_ALL),
         os.path.join(self.output_dir_actual, 'compare_rendered_pictures.json'))
 
   def _generate_skps_and_run_render_pictures(self, subdir, skpdict):
     """Generate SKPs and run render_pictures on them.
 
@@ skipping 45 matching lines @@
   """Mock version of BaseComparisons.get_timestamp() for testing."""
   return 12345678
 
 
 def main():
   base_unittest.main(CompareRenderedPicturesTest)
 
 
 if __name__ == '__main__':
   main()