Fix inert-node-is-unselectable.tentative.html.

Seems legit to select the whitespace around the inert node.

Differential Revision: https://phabricator.services.mozilla.com/D112718

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1706301
gecko-commit: 5d02922bd6d4b03034e5ed5535b8d8f2477e3da9
gecko-reviewers: masayuki
diff --git a/inert/inert-node-is-unselectable.tentative.html b/inert/inert-node-is-unselectable.tentative.html
index 7d5e908..b99af0d 100644
--- a/inert/inert-node-is-unselectable.tentative.html
+++ b/inert/inert-node-is-unselectable.tentative.html
@@ -13,7 +13,7 @@
 <script>
 test(function() {
     document.execCommand('SelectAll');
-    assert_equals(window.getSelection().toString(), "I'm selectable.");
+    assert_equals(window.getSelection().toString().trim(), "I'm selectable.");
 }, "Inert nodes cannot be selected.");
 </script>
 </body>