Point to build requirements page when there is a dependency check failure.

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 40 matching lines @@
     port_name = 'win'
 
     # FIXME: Figure out how to unify this with base.TestConfiguration.all_systems()?
     SUPPORTED_VERSIONS = ('xp', 'win7')
 
     FALLBACK_PATHS = { 'win7': [ 'win' ]}
     FALLBACK_PATHS['xp'] = ['win-xp'] + FALLBACK_PATHS['win7']
 
     DEFAULT_BUILD_DIRECTORIES = ('build', 'out')
 
+    BUILD_REQUIREMENTS_URL = 'http://www.chromium.org/developers/how-tos/build-instructions-windows'
+
     @classmethod
     def determine_full_port_name(cls, host, options, port_name):
         if port_name.endswith('win'):
             assert host.platform.is_win()
             # We don't maintain separate baselines for vista, so we pretend it is win7.
             if host.platform.os_version in ('vista', '7sp0', '7sp1', 'future'):
                 version = 'win7'
             else:
                 version = host.platform.os_version
             port_name = port_name + '-' + version
@@ skipping 182 matching lines @@
         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()