Remove all support for cygwin in run-webkit-tests.

third_party/WebKit/Tools/Scripts/webkitpy/common/system/platform_info.py

 # Copyright (c) 2011 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 38 matching lines @@
         self._platform_module = platform_module
         self.os_name = self._determine_os_name(sys_module.platform)
         if self.os_name == 'linux':
             self.os_version = self._determine_linux_version(platform_module)
         if self.os_name == 'freebsd':
             self.os_version = platform_module.release()
         if self.os_name.startswith('mac'):
             self.os_version = self._determine_mac_version(platform_module.mac_ver()[0])
         if self.os_name.startswith('win'):
             self.os_version = self._determine_win_version(self._win_version_tuple(sys_module))
-        self._is_cygwin = sys_module.platform == 'cygwin'
+        assert sys.platform != 'cygwin', 'Cygwin is not supported.'
 
     def is_mac(self):
         return self.os_name == 'mac'
 
     def is_win(self):
         return self.os_name == 'win'
 
-    def is_cygwin(self):
-        return self._is_cygwin
-
     def is_linux(self):
         return self.os_name == 'linux'
 
     def is_freebsd(self):
         return self.os_name == 'freebsd'
 
     def is_highdpi(self):
         if self.is_mac():
             output = self._executive.run_command(['system_profiler', 'SPDisplaysDataType'],
                                                  error_handler=self._executive.ignore_error)
@@ skipping 52 matching lines @@
         if self._filesystem.exists('/etc/arch-release'):
             return 'arch'
 
         return 'unknown'
 
     def _determine_os_name(self, sys_platform):
         if sys_platform == 'darwin':
             return 'mac'
         if sys_platform.startswith('linux'):
             return 'linux'
-        if sys_platform in ('win32', 'cygwin'):
+        if sys_platform == 'win32':
             return 'win'
         if sys_platform.startswith('freebsd'):
             return 'freebsd'
         raise AssertionError('unrecognized platform string "%s"' % sys_platform)
 
     def _determine_mac_version(self, mac_version_string):
         minor_release = int(mac_version_string.split('.')[1])
         assert minor_release >= 9, 'Unsupported mac OS version: %s' % mac_version_string
         if minor_release <= 12:
             return 'mac10.%d' % minor_release
@@ skipping 27 matching lines @@
         if hasattr(sys_module, 'getwindowsversion'):
             return sys_module.getwindowsversion()
         return self._win_version_tuple_from_cmd()
 
     def _win_version_tuple_from_cmd(self):
         # Note that this should only ever be called on windows, so this should always work.
         ver_output = self._executive.run_command(['cmd', '/c', 'ver'], decode_output=False)
         match_object = re.search(r'(?P<major>\d+)\.(?P<minor>\d)\.(?P<build>\d+)', ver_output)
         assert match_object, 'cmd returned an unexpected version string: ' + ver_output
         return tuple(map(int, match_object.groups()))