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

Tools/Scripts/webkitpy/layout_tests/port/base.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 112 matching lines @@
         'android': ['icecreamsandwich'],
     }
 
     DEFAULT_BUILD_DIRECTORIES = ('out',)
 
     # overridden in subclasses.
     FALLBACK_PATHS = {}
 
     SUPPORTED_VERSIONS = []
 
+    # URL to the build requirements page.
+    BUILD_REQUIREMENTS_URL = ''
+
     @classmethod
     def latest_platform_fallback_path(cls):
         return cls.FALLBACK_PATHS[cls.SUPPORTED_VERSIONS[-1]]
 
     @classmethod
     def _static_build_path(cls, filesystem, build_directory, chromium_base, configuration, comps):
         if build_directory:
             return filesystem.join(build_directory, configuration, *comps)
 
         hits = []
@@ skipping 233 matching lines @@
 
         def error_handler(script_error):
             local_error.exit_code = script_error.exit_code
 
         output = self._executive.run_command(cmd, error_handler=error_handler)
         if local_error.exit_code:
             _log.error('System dependencies check failed.')
             _log.error('To override, invoke with --nocheck-sys-deps')
             _log.error('')
             _log.error(output)
+            if self.BUILD_REQUIREMENTS_URL is not '':
+                _log.error('')
+                _log.error('For complete build requirements, please see:')
+                _log.error(self.BUILD_REQUIREMENTS_URL)
             return test_run_results.SYS_DEPS_EXIT_STATUS
         return test_run_results.OK_EXIT_STATUS
 
     def check_image_diff(self, override_step=None, logging=True):
         """This routine is used to check whether image_diff binary exists."""
         image_diff_path = self._path_to_image_diff()
         if not self._filesystem.exists(image_diff_path):
             _log.error("image_diff was not found at %s" % image_diff_path)
             return False
         return True
@@ skipping 1350 matching lines @@
             if name.find('/') != -1:
                 _log.error("Virtual test suites names cannot contain /'s: %s" % name)
                 return
             self.name = 'virtual/' + name + '/' + base
         self.base = base
         self.args = args
         self.tests = tests or set()
 
     def __repr__(self):
         return "VirtualTestSuite('%s', '%s', %s)" % (self.name, self.base, self.args)