Use OS-specific modifier key for 'select all text' command in toolbar_toolbar test

test/tests/toolbar_toolbar.js

@@ -7,6 +7,7 @@ const assertAttributeValues = require('../util/assertAttributeValues');
 const assertRovingTabindex = require('../util/assertRovingTabindex');
 const assertHasFocus = require('../util/assertHasFocus');
 const assertAttributeCanBeToggled = require('../util/assertAttributeCanBeToggled');
+const getOSPreferredModifierKey = require('../util/getOSPreferredModifierKey');
 
 const exampleFile = 'content/patterns/toolbar/examples/toolbar.html';
 
@@ -1115,7 +1116,8 @@ ariaTest(
   'toolbar-button-enter-or-space',
   async (t) => {
     let textarea = await t.context.session.findElement(By.css('textarea'));
-    await textarea.sendKeys(Key.chord(Key.CONTROL, 'a'));
+    let modifierKey = getOSPreferredModifierKey();
+    await textarea.sendKeys(Key.chord(modifierKey, 'a'));
     let originalText = await textarea.getAttribute('value');
 
     const buttons = await t.context.queryElements(
@@ -1206,7 +1208,8 @@ ariaTest(
   'toolbar-button-enter-or-space',
   async (t) => {
     let textarea = await t.context.session.findElement(By.css('textarea'));
-    await textarea.sendKeys(Key.chord(Key.CONTROL, 'a'));
+    let modifierKey = getOSPreferredModifierKey();
+    await textarea.sendKeys(Key.chord(modifierKey, 'a'));
     let originalText = await textarea.getAttribute('value');
 
     const buttons = await t.context.queryElements(

test/util/getOSPreferredModifierKey.js

@@ -0,0 +1,6 @@
+const { Key } = require('selenium-webdriver');
+const isMacOS = require('./isMacOS');
+
+module.exports = function getOSPreferredModifierKey() {
+  return isMacOS() ? Key.META : Key.CONTROL;
+};

test/util/isMacOS.js

@@ -0,0 +1,3 @@
+module.exports = function isMacOS() {
+  return process.platform === 'darwin';
+};