Disable wdiff on Windows.

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

 # Copyright (C) 2010 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 209 matching lines @@
 
     def _path_to_crash_service(self):
         binary_name = 'content_shell_crash_service.exe'
         return self._build_path(binary_name)
 
     def _path_to_image_diff(self):
         binary_name = 'image_diff.exe'
         return self._build_path(binary_name)
 
     def _path_to_wdiff(self):
-        return self.path_from_chromium_base('third_party', 'cygwin', 'bin', 'wdiff.exe')
+        # 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

[qyearsley, 2016/12/06 01:46:59]

Note, there are also other ways to disable wdiff temporarily, including changing
the place where it's invoked in the base Port class
(https://cs.chromium.org/chromium/src/third_party/WebKit/Tools/Scripts/webkitp...),
let me know if there's a better way to do it than this :-)

 
     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")
         if not result:
             _log.error("    Could not find crash service, unexpected crashes won't be symbolized.")
             _log.error('    Did you build the target blink_tests?')
             _log.error('')
         return result
 
     def look_for_new_crash_logs(self, crashed_processes, start_time):
         if self.get_option('disable_breakpad'):
             return None
         return self._dump_reader.look_for_new_crash_logs(crashed_processes, start_time)
 
     def clobber_old_port_specific_results(self):
         if not self.get_option('disable_breakpad'):
             self._dump_reader.clobber_old_results()