Reenable feature policy control over fullscreen

third_party/WebKit/LayoutTests/external/wpt_automation/fullscreen/auto-click.js

 (function() {
 
 // Gets the offset of an element in coordinates relative to the top-level frame.
 function offset(element) {
   const rect = element.getBoundingClientRect();
   const iframe = element.ownerDocument.defaultView.frameElement;
   if (!iframe) {
     return { left: rect.left, top: rect.top };
   }
   const outerOffset = offset(iframe);
@@ skipping 26 matching lines @@
 
 function observe(target) {
   observer.observe(target, { childList: true, subtree: true });
 }
 
 // Handle what's already in the document.
 for (const button of document.getElementsByTagName('button')) {
   click(button);
 }
 for (const iframe of document.getElementsByTagName('iframe')) {
-  observe(iframe.contentDocument);
-  iframe.addEventListener('load', () => {
+  try {
     observe(iframe.contentDocument);
-  });
+    iframe.addEventListener('load', () => {
+      observe(iframe.contentDocument);
+    });
+  } catch (e) {
+    // Skip cross-origin iframes, but report other errors
+    if (e.name != "SecurityError") {
+        throw e;
+    }
+  }
 }
 
 // Observe future changes.
 observe(document);
 
 })();