Always use html_diff to generate -pretty-diff.html files.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer.py
index fece01aa563ccec68fa3c4600c98a280cd5398e8..fc70eec5f2f3f53fe7d4d5c937ef69eb0bb1873f 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer.py
@@ -29,6 +29,7 @@
 
 import logging
 
+from webkitpy.common.html_diff import html_diff
 from webkitpy.layout_tests.controllers import repaint_overlay
 from webkitpy.layout_tests.models import test_failures
 
@@ -113,7 +114,7 @@ class TestResultWriter(object):
     FILENAME_SUFFIX_SAMPLE = "-sample"
     FILENAME_SUFFIX_LEAK_LOG = "-leak-log"
     FILENAME_SUFFIX_WDIFF = "-wdiff.html"
-    FILENAME_SUFFIX_PRETTY_PATCH = "-pretty-diff.html"
+    FILENAME_SUFFIX_HTML_DIFF = "-pretty-diff.html"
     FILENAME_SUFFIX_IMAGE_DIFF = "-diff.png"
     FILENAME_SUFFIX_IMAGE_DIFFS_HTML = "-diffs.html"
     FILENAME_SUFFIX_OVERLAY = "-overlay.html"
@@ -199,11 +200,10 @@ class TestResultWriter(object):
         if not actual_text or not expected_text:
             return
 
+        # Output a plain-text diff file.
         file_type = '.txt'
         actual_filename = self.output_filename(self.FILENAME_SUFFIX_ACTUAL + file_type)
         expected_filename = self.output_filename(self.FILENAME_SUFFIX_EXPECTED + file_type)
-        # We treat diff output as binary. Diff output may contain multiple files
-        # in conflicting encodings.
         diff = self._port.diff_text(expected_text, actual_text, expected_filename, actual_filename)
         diff_filename = self.output_filename(self.FILENAME_SUFFIX_DIFF + file_type)
         self._write_file(diff_filename, diff)
@@ -214,11 +214,10 @@ class TestResultWriter(object):
             wdiff_filename = self.output_filename(self.FILENAME_SUFFIX_WDIFF)
             self._write_file(wdiff_filename, wdiff)
 
-        # Use WebKit's PrettyPatch.rb to get an HTML diff.
-        if self._port.pretty_patch_available():
-            pretty_patch = self._port.pretty_patch_text(diff_filename)
-            pretty_patch_filename = self.output_filename(self.FILENAME_SUFFIX_PRETTY_PATCH)
-            self._write_file(pretty_patch_filename, pretty_patch)
+        # Output a HTML diff file.
+        html_diff_filename = self.output_filename(self.FILENAME_SUFFIX_HTML_DIFF)
+        html_diff_contents = html_diff(expected_text, actual_text)
+        self._write_file(html_diff_filename, html_diff_contents)
 
     def create_repaint_overlay_result(self, actual_text, expected_text):
         html = repaint_overlay.generate_repaint_overlay_html(self._test_name, actual_text, expected_text)