Support redirectUrl at onHeadersReceived in WebRequest / DWR API

chrome/common/extensions/api/web_request.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "webRequest",
     "description": "Use the <code>chrome.webRequest</code> API to observe and analyze traffic and to intercept, block, or modify requests in-flight.",
     "properties": {
       "MAX_HANDLER_BEHAVIOR_CHANGED_CALLS_PER_10_MINUTES": {
@@ skipping 48 matching lines @@
         "description": "Returns value for event handlers that have the 'blocking' extraInfoSpec applied. Allows the event handler to modify network requests.",
         "properties": {
           "cancel": {
             "type": "boolean",
             "optional": true,
             "description": "If true, the request is cancelled. Used in onBeforeRequest, this prevents the request from being sent."
           },
           "redirectUrl": {
             "type": "string",
             "optional": true,
-            "description": "Only used as a response to the onBeforeRequest event. If set, the original request is prevented from being sent and is instead redirected to the given URL."
+            "description": "Only used as a response to the onBeforeRequest and onHeadersReceived events. If set, the original request is prevented from being sent/completed and is instead redirected to the given URL. Redirections to non-HTTP schemes such as data: are allowed. Redirects initiated by a redirect action use the original request method for the redirect, with one exception: If the redirect is initiated at the onHeadersReceived stage, then the redirect will be issued using the GET method."
           },
           "requestHeaders": {
             "$ref": "HttpHeaders",
             "optional": true,
             "description": "Only used as a response to the onBeforeSendHeaders event. If set, the request is made with these request headers instead."
           },
           "responseHeaders": {
             "$ref": "HttpHeaders",
             "optional": true,
             "description": "Only used as a response to the onHeadersReceived event. If set, the server is assumed to have responded with these response headers instead. Only return <code>responseHeaders</code> if you really want to modify the headers in order to limit the number of conflicts (only one extension may modify <code>responseHeaders</code> for each request)."
@@ skipping 454 matching lines @@
           {
             "$ref": "RequestFilter",
             "name": "filter",
             "description": "A set of filters that restricts the events that will be sent to this listener."
           }
         ]
       }
     ]
   }
 ]