feat: add LabelButton API

lib/browser/api/label-button.js

@@ -0,0 +1,15 @@
+'use strict'
+
+const electron = require('electron')
+
+const {Button} = electron
+const {LabelButton} = process.atomBinding('label_button')
+
+Object.setPrototypeOf(LabelButton.prototype, Button.prototype)
+
+LabelButton.prototype._init = function () {
+  // Call parent class's _init.
+  Button.prototype._init.call(this)
+}
+
+module.exports = LabelButton

lib/browser/api/module-list.js

@@ -11,6 +11,7 @@ module.exports = [
   {name: 'globalShortcut', file: 'global-shortcut'},
   {name: 'ipcMain', file: 'ipc-main'},
   {name: 'inAppPurchase', file: 'in-app-purchase'},
+  {name: 'LabelButton', file: 'label-button'},
   {name: 'LayoutManager', file: 'layout-manager'},
   {name: 'Menu', file: 'menu'},
   {name: 'MenuItem', file: 'menu-item'},