Bug 1594786 - Part 1 - Add withHandlingUserInput function to extension test suite. r=rpl

Differential Revision: https://phabricator.services.mozilla.com/D53981

--HG--
extra : moz-landing-system : lando

toolkit/components/extensions/child/ext-test.js

@@ -111,6 +111,13 @@ this.test = class extends ExtensionAPI {
 
     return {
       test: {
+        withHandlingUserInput(callback) {
+          ExtensionCommon.withHandlingUserInput(
+            context.contentWindow,
+            callback
+          );
+        },
+
         sendMessage(...args) {
           extension.emit("test-message", ...args);
         },

toolkit/components/extensions/schemas/test.json

@@ -9,6 +9,14 @@
     "defaultContexts": ["content", "devtools"],
     "description": "none",
     "functions": [
+      {
+        "name": "withHandlingUserInput",
+        "type": "function",
+        "description": "Calls the callback function wrapped with user input set.  This is only used for internal unit testing.",
+        "parameters": [
+          {"type": "function", "name": "callback"}
+        ]
+      },
       {
         "name": "notifyFail",
         "type": "function",