Adds syncedNotificationsPrivate API IDL.

chrome/common/extensions/api/_api_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.
 
 // See c/c/e/features/* to understand this file, in particular feature.h,
 // simple_feature.h, and base_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 661 matching lines @@
     "contexts": ["blessed_extension", "unblessed_extension", "content_script"]
   },
   "streamsPrivate": {
     "dependencies": ["permission:streamsPrivate"],
     "contexts": ["blessed_extension"]
   },
   "syncFileSystem": {
     "dependencies": ["permission:syncFileSystem"],
     "contexts": ["blessed_extension"]
   },
+  "syncedNotificationsPrivate": {
+    "channel": "dev",

[not at google - send to devlin, 2014/05/02 21:37:38]

channel restriction should be on the permission not the API; though I see it
already is

[dewittj, 2014/05/03 00:07:49]

Done.

+    "contexts": ["blessed_extension"],
+    "dependencies": ["permission:syncedNotificationsPrivate"]
+  },
   "systemIndicator": {
     "dependencies": ["manifest:system_indicator"],
     "contexts": ["blessed_extension"]
   },
   "system.cpu": {
     "dependencies": ["permission:system.cpu"],
     "contexts": ["blessed_extension"]
   },
   "system.display": {
     "dependencies": ["permission:system.display"],
@@ skipping 125 matching lines @@
     "internal": true,
     "channel": "stable",
     "dependencies": ["permission:webview"],
     "contexts": ["blessed_extension"]
   },
   "windows": {
     "dependencies": ["api:tabs"],
     "contexts": ["blessed_extension"]
   }
 }