Use Referrer-Policy headers for CSS stylesheets

third_party/WebKit/LayoutTests/external/wpt/referrer-policy/generic/subresource/subresource.py

 import os, sys, json, urlparse, urllib
 
 def get_template(template_basename):
     script_directory = os.path.dirname(os.path.abspath(__file__))
     template_directory = os.path.abspath(os.path.join(script_directory,
                                                       "..",
                                                       "template"))
     template_filename = os.path.join(template_directory, template_basename);
 
     with open(template_filename, "r") as f:
@@ skipping 54 matching lines @@
 def __noop(request, response):
     return ""
 
 
 def respond(request,
             response,
             status_code = 200,
             content_type = "text/html",
             payload_generator = __noop,
             cache_control = "no-cache; must-revalidate",
-            access_control_allow_origin = "*"):
+            access_control_allow_origin = "*",
+            maybe_additional_headers = None):
     if preprocess_redirection(request, response):
         return
 
     response.add_required_headers = False
     response.writer.write_status(status_code)
 
     if access_control_allow_origin != None:
         response.writer.write_header("access-control-allow-origin",
                                      access_control_allow_origin)
     response.writer.write_header("content-type", content_type)
     response.writer.write_header("cache-control", cache_control)
+
+    additional_headers = maybe_additional_headers or {}
+    for header, value in additional_headers.items():
+        response.writer.write_header(header, value)
+
     response.writer.end_headers()
 
     server_data = {"headers": json.dumps(request.headers, indent = 4)}
 
     payload = payload_generator(server_data)
     response.writer.write(payload)