Remove use of wdiff from layout test runner.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/win.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/win.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/win.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/win.py
index 863d88655a7b65ee2fed6e39c6bc7eef0ce20738..8d6cabdf09c3ba4098b9583ab5c7769f1e9e41e7 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/win.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/win.py
@@ -227,12 +227,6 @@ class WinPort(base.Port):
         binary_name = 'image_diff.exe'
         return self._build_path(binary_name)
 
-    def _path_to_wdiff(self):
-        # Temporarily disabling wdiff on Windows to see how this affects
-        # the rate of layout test hanging on try bots (http://crbug.com/637478).
-        # TODO(qyearsley): Re-enable this when possible.
-        return None
-
     def _check_crash_service_available(self):
         """Checks whether the crash service binary is present."""
         result = self._check_file_exists(self._path_to_crash_service(), "content_shell_crash_service.exe")