Bug 1660781 - Lazily load all external modules in Marionette's JSWindowActor classes. r=marionette-reviewers,maja_zf

To prevent performance degration and extra memory usage in Firefox
for newly spawned content processes, only load external modules if
required in both the parent and child actor.

Differential Revision: https://phabricator.services.mozilla.com/D88138

testing/marionette/actors/MarionetteFrameChild.jsm

@@ -10,14 +10,12 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 
-const { element } = ChromeUtils.import(
-  "chrome://marionette/content/element.js"
-);
-const { error } = ChromeUtils.import("chrome://marionette/content/error.js");
-const { evaluate } = ChromeUtils.import(
-  "chrome://marionette/content/evaluate.js"
-);
-const { Log } = ChromeUtils.import("chrome://marionette/content/log.js");
+XPCOMUtils.defineLazyModuleGetters(this, {
+  element: "chrome://marionette/content/element.js",
+  error: "chrome://marionette/content/error.js",
+  evaluate: "chrome://marionette/content/evaluate.js",
+  Log: "chrome://marionette/content/log.js",
+});
 
 XPCOMUtils.defineLazyGetter(this, "logger", Log.get);
 

testing/marionette/actors/MarionetteFrameParent.jsm

@@ -10,15 +10,13 @@ const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 
-const { EventEmitter } = ChromeUtils.import(
-  "resource://gre/modules/EventEmitter.jsm"
-);
+XPCOMUtils.defineLazyModuleGetters(this, {
+  EventEmitter: "resource://gre/modules/EventEmitter.jsm",
 
-const { error } = ChromeUtils.import("chrome://marionette/content/error.js");
-const { evaluate } = ChromeUtils.import(
-  "chrome://marionette/content/evaluate.js"
-);
-const { Log } = ChromeUtils.import("chrome://marionette/content/log.js");
+  error: "chrome://marionette/content/error.js",
+  evaluate: "chrome://marionette/content/evaluate.js",
+  Log: "chrome://marionette/content/log.js",
+});
 
 XPCOMUtils.defineLazyGetter(this, "logger", Log.get);