Bug 1824491 - Convert browser/actors/LightweightThemeChild.jsm to ESM. r=kpatenio

Differential Revision: https://phabricator.services.mozilla.com/D174521

browser/actors/LightweightThemeChild.sys.mjs

@@ -2,14 +2,10 @@
  * 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";
-
-var EXPORTED_SYMBOLS = ["LightweightThemeChild"];
-
 /**
  * LightweightThemeChild forwards theme data to in-content pages.
  */
-class LightweightThemeChild extends JSWindowActorChild {
+export class LightweightThemeChild extends JSWindowActorChild {
   constructor() {
     super();
     this._initted = false;

browser/actors/moz.build

@@ -13,7 +13,7 @@ with Files("ContentSearch*.sys.mjs"):
 with Files("AboutReaderParent.jsm"):
     BUG_COMPONENT = ("Toolkit", "Reader Mode")
 
-with Files("LightweightThemeChild.jsm"):
+with Files("LightweightThemeChild.sys.mjs"):
     BUG_COMPONENT = ("WebExtensions", "Themes")
 
 with Files("PageInfoChild.sys.mjs"):
@@ -64,7 +64,7 @@ FINAL_TARGET_FILES.actors += [
     "EncryptedMediaParent.sys.mjs",
     "FormValidationChild.sys.mjs",
     "FormValidationParent.sys.mjs",
-    "LightweightThemeChild.jsm",
+    "LightweightThemeChild.sys.mjs",
     "LinkHandlerChild.sys.mjs",
     "LinkHandlerParent.sys.mjs",
     "PageInfoChild.sys.mjs",

browser/components/BrowserGlue.sys.mjs

@@ -558,7 +558,7 @@ let JSWINDOWACTORS = {
 
   LightweightTheme: {
     child: {
-      moduleURI: "resource:///actors/LightweightThemeChild.jsm",
+      esModuleURI: "resource:///actors/LightweightThemeChild.sys.mjs",
       events: {
         pageshow: { mozSystemGroup: true },
         DOMContentLoaded: {},

toolkit/components/extensions/test/browser/browser_ext_themes_ntp_colors_perwindow.js

@@ -207,7 +207,7 @@ add_task(async function test_per_window_ntp_theme() {
     async ({ theme, isBrightText, winId }) => {
       let win = Services.wm.getOuterWindowWithId(winId);
       win.NewTabPagePreloading.removePreloadedBrowser(win);
-      // These pages were initially chosen because LightweightThemeChild.jsm
+      // These pages were initially chosen because LightweightThemeChild.sys.mjs
       // treats them specially.
       for (let url of ["about:newtab", "about:home"]) {
         info("Opening url: " + url);