Index: tracing/tracing/ui/base/polymer_preload.html |
diff --git a/tracing/tracing/ui/base/polymer_preload.html b/tracing/tracing/ui/base/polymer_preload.html |
index 8860b5befecfd08c1efda82f731a3f3c7fa3a4bb..4c21ef991ca0d1fb9cc1c3a9715928fd09317b4f 100644 |
--- a/tracing/tracing/ui/base/polymer_preload.html |
+++ b/tracing/tracing/ui/base/polymer_preload.html |
@@ -8,8 +8,9 @@ found in the LICENSE file. |
'use strict'; |
// Force Polymer into native shadowDom mode |
-if (window.Polymer) |
+if (window.Polymer) { |
throw new Error('Cannot proceed. Polymer already present.'); |
+} |
window.Polymer = {}; |
window.Polymer.dom = 'shadow'; |
</script> |