Chromium side changes to add the ledger API.

chrome/common/extensions/api/_permission_features.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.
 
 // This features file defines permissions for extension APIs implemented
 // under src/chrome.
 // See extensions/common/features/* to understand this file, in particular
 // feature.h, simple_feature.h, and base_feature_provider.h.
 
 // To add a new whitelisted ID, SHA-1 it and force it to uppercase. In Bash:
@@ skipping 484 matching lines @@
       "3010EF507AFEF487EEA9CDE2930EC94867C60936",  // Citrix Receiver Beta
       "ABAABC5F49E022A76CBB12972A53B58354C04AC6",  // Citrix Receiver Dev
       "0EA6B717932AD64C469C1CCB6911457733295907",  // HTerm
       "58B0C2968C335964D5433E89CA4D86628A0E3D4B"   // HTerm dev
     ]
   },{
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app", "platform_app"],
     "location": "component"
   }],
+  "ledger": {
+    "channel": "trunk",
+    "extension_types": ["extension", "platform_app"]
+  },
   "location": [
     {
       "channel": "dev",
       "extension_types": [
         "extension", "legacy_packaged_app", "platform_app"
       ]
     },
     {
       "channel": "stable",
       "extension_types": [
@@ skipping 463 matching lines @@
     // Only allowed for whitelisted extensions until all the caveats are
     // addressed. Tracked in crbug/285151.
     "channel": "stable",
     "extension_types": ["extension"],
     "location": "component",
     "whitelist": [
       "D519188F86D9ACCEE0412007B227D9936EB9676B"  // GAIA Component Extension
     ]
   }]
 }