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

chrome/common/extensions/docs/samples.json

 {
   "api": {
     "chrome.alarms.clear": "alarms.html#method-clear",
     "chrome.alarms.clearAll": "alarms.html#method-clearAll",
     "chrome.alarms.create": "alarms.html#method-create",
     "chrome.alarms.get": "alarms.html#method-get",
     "chrome.alarms.getAll": "alarms.html#method-getAll",
     "chrome.alarms.onAlarm": "alarms.html#event-onAlarm",
     "chrome.appWindow.create": "appWindow.html#method-create",
     "chrome.appWindow.focus": "appWindow.html#method-focus",
@@ skipping 225 matching lines @@
     "chrome.extension.onConnectExternal": "extension.html#event-onConnectExternal",
     "chrome.extension.onMessage": "extension.html#event-onMessage",
     "chrome.extension.onMessageExternal": "extension.html#event-onMessageExternal",
     "chrome.extension.sendMessage": "extension.html#method-sendMessage",
     "chrome.extension.setUpdateUrlData": "extension.html#method-setUpdateUrlData",
     "chrome.fileBrowserHandler.onExecute": "fileBrowserHandler.html#event-onExecute",
     "chrome.fileBrowserHandler.selectFile": "fileBrowserHandler.html#method-selectFile",
     "chrome.fileSystem.chooseFile": "fileSystem.html#method-chooseFile",
     "chrome.fileSystem.getDisplayPath": "fileSystem.html#method-getDisplayPath",
     "chrome.fileSystem.getWritableFileEntry": "fileSystem.html#method-getWritableFileEntry",
+    "chrome.fileSystem.isWritableFileEntry": "fileSystem.html#method-isWritableFileEntry",
     "chrome.history.addUrl": "history.html#method-addUrl",
     "chrome.history.deleteAll": "history.html#method-deleteAll",
     "chrome.history.deleteRange": "history.html#method-deleteRange",
     "chrome.history.deleteUrl": "history.html#method-deleteUrl",
     "chrome.history.getVisits": "history.html#method-getVisits",
     "chrome.history.onVisitRemoved": "history.html#event-onVisitRemoved",
     "chrome.history.onVisited": "history.html#event-onVisited",
     "chrome.history.search": "history.html#method-search",
     "chrome.i18n.getAcceptLanguages": "i18n.html#method-getAcceptLanguages",
     "chrome.i18n.getMessage": "i18n.html#method-getMessage",
@@ skipping 2528 matching lines @@
         "manifest.json",
         "popup.html",
         "popup.js",
         "sample.css"
       ],
       "source_hash": "8e51dc3a9577065d22ce92f3c838edc5ceaf4e65",
       "zip_path": "examples/api/extension/isAllowedAccess.zip"
     }
   ]
 }