Generate the Chrome policy schema at compile time.

chrome/browser/policy/DEPS

 # The //chrome/browser/policy code is being converted into a component at
 # //components/policy. This DEPS file is temporarily restricting the include
 # rules for this code; once all the exceptions are fixed then the code will
 # be moved, and this file will be removed.
 # http://crbug.com/271392
 
 include_rules = [
   "-chrome",
   "-chromeos",
   "-content",
   "+chrome/browser/policy",
   "+components/json_schema",
 ]
 
 specific_include_rules = {
   # These files will stay.
   r"(browser_policy_connector|"
   r"configuration_policy_handler_android|"
   r"configuration_policy_handler_list|"
   r"file_selection_dialogs_policy_handler|"
   r"file_selection_dialogs_policy_handler_unittest|"
+  r"generate_policy_source_unittest|"
   r"javascript_policy_handler|"
   r"javascript_policy_handler_unittest|"
   r"managed_mode_policy_provider|"
   r"policy_browsertest|"
   r"policy_path_parser|"
   r"policy_path_parser_linux|"
   r"policy_path_parser_mac|"
   r"policy_path_parser_unittest|"
   r"policy_path_parser_win|"
   r"policy_prefs_browsertest|"
   r"profile_policy_connector|"
   r"profile_policy_connector_factory|"
   r"url_blacklist_manager|"
   r"url_blacklist_manager_unittest|"
   r"url_blacklist_policy_handler|"
   r"url_blacklist_policy_handler_unittest)"
   r"\.(cc|h)": [
     "+chrome",
     "+chromeos",
     "+content/public/browser",
     "+content/public/common",
     "+content/public/test",
     "+content/test/net",
   ],
 }