Introduce chrome.displaySource API

extensions/common/api/_permission_features.json

 // Copyright 2014 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 permissions for extension APIs implemented
 // under src/extensions.
 
 // See extensions/common/features/* to understand this file, in particular
 // feature.h, simple_feature.h, and base_feature_provider.h.
 
@@ skipping 166 matching lines @@
     {
       "channel": "stable",
       "extension_types": ["platform_app"],
       "whitelist": [
         "7AE714FFD394E073F0294CFA134C9F91DB5FBAA4",  // CCD Development
         "C7DA3A55C2355F994D3FDDAD120B426A0DF63843",  // CCD Testing
         "75E3CFFFC530582C583E4690EF97C70B9C8423B7"   // CCD Release
       ]
     }
   ],
+  "displaySource": {
+    "channel": "dev",
+    "extension_types": ["extension", "platform_app"]
+  },
   "dns": [
     {
       "channel": "dev",
       "extension_types": ["extension", "platform_app"]
     },
     {
       "channel": "stable",
       "extension_types": ["extension", "platform_app"],
       "whitelist": [
         "7AE714FFD394E073F0294CFA134C9F91DB5FBAA4",  // CCD Development
@@ skipping 281 matching lines @@
   }],
   "webRequest": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]
    },
   "webRequestBlocking": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]
   }
 }