1 files changed, 11 insertions, 4 deletions
diff --git a/layout/reftests/webcomponents/input-transition-1.html b/layout/reftests/webcomponents/input-transition-1.html
index c11444d05..a4be5271b 100644
--- a/layout/reftests/webcomponents/input-transition-1.html
+++ b/layout/reftests/webcomponents/input-transition-1.html
@@ -7,9 +7,11 @@
     <script>
       var host, root;
 
-      host = document.getElementById("host");
-      root = host.attachShadow({mode: 'open'});
-      root.innerHTML = '<style>input ~ div { background: red; transition: background 100ms; } input:checked ~ div { background: green; }</style><input id="one" type="checkbox"><div style="height: 50px; width: 50px;"></div>';
+      function run() {
+        host = document.getElementById("host");
+        root = host.createShadowRoot();
+        root.innerHTML = '<style>input ~ div { background: red; transition: background 100ms; } input:checked ~ div { background: green; }</style><input id="one" type="checkbox"><div style="height: 50px; width: 50px;"></div>';
+      }
 
       function tweak() {
         var el = root.getElementById("one");
@@ -19,7 +21,12 @@
         });
       }
 
-      window.addEventListener("MozReftestInvalidate", tweak);
+      if (document.body.createShadowRoot) {
+        run();
+        window.addEventListener("MozReftestInvalidate", tweak);
+      } else {
+        document.documentElement.className = "";
+      }
     </script>
   </body>
 </html>