Add Resource Handler for creating Streams to forward to extensions

chrome/common/extensions/api/streams_private.json

 // Copyright (c) 2013 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":"streamsPrivate",
     "types": [
     ],
 
     "events": [
       {
         "name": "onExecuteMimeTypeHandler",
         "type": "function",
         "description": "Fired when a resource is fetched which matches a mime type handled by this extension. The resource request is cancelled, and the extension is expected to handle the request. The event is restricted to a small number of white-listed extensions.",
         "parameters": [
           {
             "name": "mimeType",
             "type": "string",
             "description": "The MIME type of the intercepted URL request."
           },
           {
             "name": "originalUrl",
             "type": "string",
             "description": "The original URL that was intercepted."
+          },
+          {
+            "name": "streamUrl",
+            "type": "string",
+            "description": "The URL that the stream can be read from."
           }
         ]
       }
     ],
 
     "functions": [
     ]
   }
 ]