DesktopArticleTarget: Make the waiting module list extensible

So that GlobalCssJs and other extensions can hook in.

Bug: T156899
Change-Id: I045c7b045ce28047298b28a05e77ef27749c1ee1

VisualEditor.hooks.php

@@ -699,6 +699,7 @@ class VisualEditorHooks {
 
 		$vars['wgVisualEditorConfig'] = [
 			'disableForAnons' => $veConfig->get( 'VisualEditorDisableForAnons' ),
+			'preloadModules' => $veConfig->get( 'VisualEditorPreloadModules' ),
 			'preferenceModules' => $veConfig->get( 'VisualEditorPreferenceModules' ),
 			'namespaces' => $availableNamespaces,
 			'contentModels' => $availableContentModels,

extension.json

@@ -27,6 +27,10 @@
 		"VisualEditorPreferenceModules": {
 			"visualeditor-enable-experimental": "ext.visualEditor.experimental"
 		},
+		"VisualEditorPreloadModules": [
+			"site",
+			"user"
+		],
 		"VisualEditorRestbaseURL": false,
 		"VisualEditorFullRestbaseURL": false,
 		"VisualEditorFeedbackAPIURL": false,

modules/ve-mw/init/targets/ve.init.mw.DesktopArticleTarget.init.js

@@ -127,10 +127,9 @@
 			targetPromise = mw.loader.using( 'ext.visualEditor.targetLoader' )
 				.then( function () {
 					mw.libs.ve.targetLoader.addPlugin( function () {
-						// If the user and site modules fail, we still want to continue
+						// Run VisualEditorPreloadModules, but if they fail, we still want to continue
 						// loading, so convert failure to success
-
-						return mw.loader.using( [ 'user', 'site' ] ).then(
+						return mw.loader.using( conf.preloadModules ).then(
 							null,
 							function () {
 								return $.Deferred().resolve();