Allow spellcheck_test to run custom callback at completion

third_party/WebKit/LayoutTests/editing/spelling/spellcheck_test.html

Index: third_party/WebKit/LayoutTests/editing/spelling/spellcheck_test.html
diff --git a/third_party/WebKit/LayoutTests/editing/spelling/spellcheck_test.html b/third_party/WebKit/LayoutTests/editing/spelling/spellcheck_test.html
index 23b5cd8fc475815f40b600fec17ecf73e639e5ff..033a821407301e1e473f434b882310abeebc541a 100644
--- a/third_party/WebKit/LayoutTests/editing/spelling/spellcheck_test.html
+++ b/third_party/WebKit/LayoutTests/editing/spelling/spellcheck_test.html
@@ -44,5 +44,24 @@ spellcheck_test(
     '<input type="text" value="_asd_.">',
     'Mark misspellings in <input>.');
 
+spellcheck_test(
+    '<div contenteditable spellcheck="false">zz.|</div>',
+    '',
+    '<div contenteditable spellcheck="false">zz.</div>',
+    {
+      title: 'No marker on misspelled word when spellcheck=false.',
+      callback: sample => spellcheck_test(
+          sample,
+          document => {
+            const div = document.querySelector('div');
+            div.setAttribute('spellcheck', 'true');
+            // Trigger spellchecker by selection change.
+            document.getSelection().collapse(div, 0);
+          },
+          '<div contenteditable spellcheck="true">_zz_.</div>',
+          'Marker appears after setting spellcheck=true.'
+      )
+    });
+
 // TODO(xiaochengh): Design interface for checking marker description.
 </script>