--- a/browser/base/content/test/performance/browser_urlbar_keyed_search.js
+++ b/browser/base/content/test/performance/browser_urlbar_keyed_search.js
@@ -78,16 +78,47 @@ const EXPECTED_REFLOWS_FIRST_OPEN = [
       "_openAutocompletePopup@chrome://browser/content/urlbarBindings.xml",
       "openAutocompletePopup@chrome://browser/content/urlbarBindings.xml",
       "openPopup@chrome://global/content/bindings/autocomplete.xml",
       "set_popupOpen@chrome://global/content/bindings/autocomplete.xml",
     ],
   },
 ];
 
+// These extra reflows happen on beta/release as one of the default bookmarks in
+// bookmarks.html.in has a long URL.
+if (AppConstants.RELEASE_OR_BETA) {
+  EXPECTED_REFLOWS_FIRST_OPEN.push({
+    stack: [
+      "_handleOverflow@chrome://global/content/bindings/autocomplete.xml",
+      "_onUnderflow@chrome://global/content/bindings/autocomplete.xml",
+      "onunderflow@chrome://browser/content/browser.xul",
+    ],
+    maxCount: 6,
+  });
+  EXPECTED_REFLOWS_FIRST_OPEN.push({
+    stack: [
+      "_handleOverflow@chrome://global/content/bindings/autocomplete.xml",
+      "_onOverflow@chrome://global/content/bindings/autocomplete.xml",
+      "onoverflow@chrome://browser/content/browser.xul",
+    ],
+    maxCount: 6,
+  });
+  EXPECTED_REFLOWS_FIRST_OPEN.push({
+    stack: [
+      "_handleOverflow@chrome://global/content/bindings/autocomplete.xml",
+      "_adjustAcItem@chrome://global/content/bindings/autocomplete.xml",
+      "_appendCurrentResult@chrome://global/content/bindings/autocomplete.xml",
+      "_invalidate@chrome://global/content/bindings/autocomplete.xml",
+      "invalidate@chrome://global/content/bindings/autocomplete.xml",
+    ],
+    maxCount: 12,
+  });
+}
+
 /**
  * Returns a Promise that resolves once the AwesomeBar popup for a particular
  * window has appeared after having done a search for its input text.
  *
  * @param win (browser window)
  *        The window to do the search in.
  * @returns Promise
  */