1 files changed, 8 insertions, 4 deletions
diff --git a/gfx/layers/FrameMetrics.h b/gfx/layers/FrameMetrics.h
index 6b7a41bf25..5d13d36703 100644
--- a/gfx/layers/FrameMetrics.h
+++ b/gfx/layers/FrameMetrics.h
@@ -243,11 +243,9 @@ struct FrameMetrics {
   }
 
   /*
-   * Returns true if the layout scroll offset or visual scroll offset changed
-   * and returns the visual scroll offset change delta.
+   * Returns true if the layout scroll offset or visual scroll offset changed.
    */
-  std::pair<bool, CSSPoint> ApplyAbsoluteScrollUpdateFrom(
-      const ScrollPositionUpdate& aUpdate);
+  bool ApplyScrollUpdateFrom(const ScrollPositionUpdate& aUpdate);
 
   /**
    * Applies the relative scroll offset update contained in aOther to the
@@ -893,6 +891,12 @@ struct ScrollMetadata {
     mScrollUpdates.AppendElements(std::move(aUpdates));
   }
 
+  void PrependUpdates(const nsTArray<ScrollPositionUpdate>& aUpdates) {
+    MOZ_ASSERT(!aUpdates.IsEmpty());
+
+    mScrollUpdates.InsertElementsAt(0, aUpdates);
+  }
+
  private:
   FrameMetrics mMetrics;