1 files changed, 29 insertions, 0 deletions
diff --git a/browser/components/extensions/child/ext-devtools-inspectedWindow.js b/browser/components/extensions/child/ext-devtools-inspectedWindow.js
new file mode 100644
index 0000000000..fdd8b97c17
--- /dev/null
+++ b/browser/components/extensions/child/ext-devtools-inspectedWindow.js
@@ -0,0 +1,29 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+/* 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.devtools_inspectedWindow = class extends ExtensionAPI {
+  getAPI(context) {
+    // `devtoolsToolboxInfo` is received from the child process when the root devtools view
+    // has been created, and every sub-frame of that top level devtools frame will
+    // receive the same information when the context has been created from the
+    // `ExtensionChild.createExtensionContext` method.
+    let tabId =
+      context.devtoolsToolboxInfo &&
+      context.devtoolsToolboxInfo.inspectedWindowTabId;
+
+    return {
+      devtools: {
+        inspectedWindow: {
+          get tabId() {
+            return tabId;
+          },
+        },
+      },
+    };
+  }
+};