1 files changed, 27 insertions, 0 deletions
diff --git a/toolkit/content/widgets/general.js b/toolkit/content/widgets/general.js
new file mode 100644
index 0000000000..14003a7558
--- /dev/null
+++ b/toolkit/content/widgets/general.js
@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// This is loaded into chrome windows with the subscript loader. Wrap in
+// a block to prevent accidentally leaking globals onto `window`.
+{
+  class MozCommandSet extends MozXULElement {
+    connectedCallback() {
+      if (this.getAttribute("commandupdater") === "true") {
+        const events = this.getAttribute("events") || "*";
+        const targets = this.getAttribute("targets") || "*";
+        document.commandDispatcher.addCommandUpdater(this, events, targets);
+      }
+    }
+
+    disconnectedCallback() {
+      if (this.getAttribute("commandupdater") === "true") {
+        document.commandDispatcher.removeCommandUpdater(this);
+      }
+    }
+  }
+
+  customElements.define("commandset", MozCommandSet);
+}