Sync requestFullscreen() and exitFullscreen() algorithms with the spec

third_party/WebKit/LayoutTests/fullscreen/api/element-request-fullscreen-and-remove-iframe.html

Index: third_party/WebKit/LayoutTests/fullscreen/api/element-request-fullscreen-and-remove-iframe.html
diff --git a/third_party/WebKit/LayoutTests/fullscreen/api/element-request-fullscreen-and-remove-iframe.html b/third_party/WebKit/LayoutTests/fullscreen/api/element-request-fullscreen-and-remove-iframe.html
index 3edb7c8aec7b057bf891f5c6642d962667e5ea30..3d0a3c465b85c355bb828e10cf4756b442c489d7 100644
--- a/third_party/WebKit/LayoutTests/fullscreen/api/element-request-fullscreen-and-remove-iframe.html
+++ b/third_party/WebKit/LayoutTests/fullscreen/api/element-request-fullscreen-and-remove-iframe.html
@@ -12,10 +12,7 @@ async_test(t => {
   const iframe = document.querySelector("iframe");
   const iframeDocument = iframe.contentDocument;
 
-  document.onfullscreenchange = t.step_func_done(() => {
-    assert_equals(document.fullscreenElement, null);
-    assert_equals(iframeDocument.fullscreenElement, null);
-  });
+  document.onfullscreenchange = t.unreached_func("fullscreenchange event");
   document.onfullscreenerror = t.unreached_func("fullscreenerror event");
   iframeDocument.onfullscreenchange = t.unreached_func("iframe fullscreenchange event");
   iframeDocument.onfullscreenerror = t.unreached_func("iframe fullscreenerror event");
@@ -23,6 +20,11 @@ async_test(t => {
   trusted_click(t.step_func(() => {
     iframeDocument.body.requestFullscreen();
     iframe.remove();
+    // No events will be fired, end test after 100ms.
+    setTimeout(t.step_func_done(() => {
+      assert_equals(document.fullscreenElement, null);
+      assert_equals(iframeDocument.fullscreenElement, null);
+    }), 100);
   }), document.body);
 });
 </script>