Convert BlobLicenseSelctors to ES6.

app/assets/javascripts/blob/blob_license_selectors.js

-(function() {
-  this.BlobLicenseSelectors = (function() {
-    function BlobLicenseSelectors(opts) {
-      var ref;
-      this.$dropdowns = (ref = opts.$dropdowns) != null ? ref : $('.js-license-selector'), this.editor = opts.editor;
-      this.$dropdowns.each((function(_this) {
-        return function(i, dropdown) {
-          var $dropdown;
-          $dropdown = $(dropdown);
-          return new BlobLicenseSelector({
-            pattern: /^(.+\/)?(licen[sc]e|copying)($|\.)/i,
-            data: $dropdown.data('data'),
-            wrapper: $dropdown.closest('.js-license-selector-wrap'),
-            dropdown: $dropdown,
-            editor: _this.editor
-          });
-        };
-      })(this));
-    }
-
-    return BlobLicenseSelectors;
-
-  })();
-
-}).call(this);

app/assets/javascripts/blob/blob_license_selectors.js.es6

+((global) => {
+  class BlobLicenseSelectors() {
+    constructor({ $dropdowns, editor }) {
+      this.$dropdowns = $('.js-license-selector');
+      this.editor = editor;
+      this.$dropdowns.each((dropdown) => {
+        const $dropdown = $(dropdown);
+        return new BlobLicenseSelector({
+          editor,
+          pattern: /^(.+\/)?(licen[sc]e|copying)($|\.)/i,
+          data: $dropdown.data('data'),
+          wrapper: $dropdown.closest('.js-license-selector-wrap'),
+          dropdown: $dropdown,
+        });
+      });
+    }
+  }
+
+  global.BlobLicenseSelectors = BlobLicenseSelectors;
+
+})(window.gl || (window.gl = {}));