1 files changed, 23 insertions, 0 deletions
diff --git a/dom/base/crashtests/1555786.html b/dom/base/crashtests/1555786.html
new file mode 100644
index 0000000000..97740ad795
--- /dev/null
+++ b/dom/base/crashtests/1555786.html
@@ -0,0 +1,23 @@
+<html>
+<head>
+  <script>
+    function start() {
+      const xhr = new XMLHttpRequest();
+      const observer = new ResizeObserver(entries => {
+        xhr.open('GET', '', false);
+        xhr.send();
+        typeof entries[0].borderBoxSize;
+        typeof entries[0].contentRect;
+        typeof entries[0].borderBoxSize;
+      })
+      observer.observe(document.getElementById('list'), {});
+      window.close();
+    }
+
+    document.addEventListener('DOMContentLoaded', start);
+  </script>
+</head>
+<body>
+  <li class="" id="list">
+</body>
+</html>