Add read-only access to POST data for webRequest's onBeforeRequest

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",
     "types": [
       {
         "id": "RequestFilter",
@@ skipping 88 matching lines @@
         "parameters": [
           {
             "type": "object",
             "name": "details",
             "properties": {
               "requestId": {"type": "string", "description": "The ID of the request. Request IDs are unique within a browser session. As a result, they could be used to relate different events of the same request."},
               "url": {"type": "string"},
               "method": {"type": "string", "description": "Standard HTTP method."},
               "frameId": {"type": "integer", "description": "The value 0 indicates that the request happens in the main frame; a positive value indicates the ID of a subframe in which the request happens. If the document of a (sub-)frame is loaded (<code>type</code> is <code>main_frame</code> or <code>sub_frame</code>), <code>frameId</code> indicates the ID of this frame, not the ID of the outer frame. Frame IDs are unique within a tab."},
               "parentFrameId": {"type": "integer", "description": "ID of frame that wraps the frame which sent the request. Set to -1 if no parent frame exists."},
+              "postData": {
+                "type": "object",
+                "optional": true,
+                "description": "POST data of the request.",
+                "properties": {},
+                "additionalProperties": {
+                  "type": "array",
+                  "items": { "type": "string" }
+                }
+              },
               "tabId": {"type": "integer", "description": "The ID of the tab in which the request takes place. Set to -1 if the request isn't related to a tab."},
               "type": {"type": "string", "enum": ["main_frame", "sub_frame", "stylesheet", "script", "image", "object", "xmlhttprequest", "other"], "description": "How the requested resource will be used."},
               "timeStamp": {"type": "number", "description": "The time when this signal is triggered, in milliseconds since the epoch."}
             }
           }
         ],
         "extraParameters": [
           {
             "$ref": "RequestFilter",
             "name": "filter",
             "description": "A set of filters that restricts the events that will be sent to this listener."
           },
           {
             "type": "array",
             "optional": true,
             "name": "extraInfoSpec",
             "description": "Array of extra information that should be passed to the listener function.",
             "items": {
               "type": "string",
-              "enum": ["blocking"]
+              "enum": ["blocking", "requestPostData"]
             }
           }
         ],
         "returns": {
           "$ref": "BlockingResponse",
           "description": "If \"blocking\" is specified in the \"extraInfoSpec\" parameter, the event listener should return an object of this type.",
           "optional": true
         }
       },
       {
@@ skipping 338 matching lines @@
           {
             "$ref": "RequestFilter",
             "name": "filter",
             "description": "A set of filters that restricts the events that will be sent to this listener."
           }
         ]
       }
     ]
   }
 ]