Introduce networking.cast API

chrome/common/extensions/api/_api_features.json

 // Copyright 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.
 
 // This features file defines extension APIs implemented under src/chrome.
 // See chrome/common/extensions/api/_features.md to understand this file, as
 // well as feature.h, simple_feature.h, and feature_provider.h.
 //
 // Note that specifying "web_page", "blessed_web_page", or "all" as a context
 // type will require manually updating chrome/renderer/resources/dispatcher.cc.
@@ skipping 594 matching lines @@
   "mimeHandlerViewGuestInternal": {
     "internal": true,
     "contexts": "all",
     "channel": "stable",
     "matches": ["<all_urls>"]
   },
   "musicManagerPrivate": {
     "dependencies": ["permission:musicManagerPrivate"],
     "contexts": ["blessed_extension"]
   },
+  "networking.castPrivate": {
+    "channel": "stable",
+    "contexts": ["blessed_extension"],
+    "dependencies": ["permission:networking.castPrivate"]
+  },
   "notifications": {
     "dependencies": ["permission:notifications"],
     "contexts": ["blessed_extension"]
   },
   "omnibox": {
     "dependencies": ["manifest:omnibox"],
     "contexts": ["blessed_extension"]
   },
   "pageAction": {
     "dependencies": ["manifest:page_action"],
@@ skipping 211 matching lines @@
     "internal": true,
     "channel": "stable",
     "dependencies": ["permission:webview"],
     "contexts": ["blessed_extension"]
   },
   "windows": {
     "dependencies": ["api:tabs"],
     "contexts": ["blessed_extension"]
   }
 }