diff --git a/dom/base/nsDOMWindowUtils.cpp b/dom/base/nsDOMWindowUtils.cpp
index 96cc3613e623..0e4a7341f807 100644
--- a/dom/base/nsDOMWindowUtils.cpp
+++ b/dom/base/nsDOMWindowUtils.cpp
@@ -1726,6 +1726,18 @@ nsDOMWindowUtils::NeedsFlush(int32_t aFlushType, bool* aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsDOMWindowUtils::FlushLayoutWithoutThrottledAnimations()
+{
+  nsCOMPtr<nsIDocument> doc = GetDocument();
+  if (doc) {
+    doc->FlushPendingNotifications(
+      ChangesToFlush(FlushType::Layout, false /* flush animations */));
+  }
+
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDOMWindowUtils::GetRootBounds(nsISupports** aResult)
 {
diff --git a/dom/interfaces/base/nsIDOMWindowUtils.idl b/dom/interfaces/base/nsIDOMWindowUtils.idl
index b65384d2e8ff..84b17c2ff1d9 100644
--- a/dom/interfaces/base/nsIDOMWindowUtils.idl
+++ b/dom/interfaces/base/nsIDOMWindowUtils.idl
@@ -856,6 +856,12 @@ interface nsIDOMWindowUtils : nsISupports {
    */
   bool needsFlush(in long aFlushtype);
 
+  /**
+   * Flush pending layout-type notification without flushing throttled
+   * animations.
+   */
+  void flushLayoutWithoutThrottledAnimations();
+
   /**
    * Returns the bounds of the window's currently loaded document. This will
    * generally be (0, 0, pageWidth, pageHeight) but in some cases (e.g. RTL