From 4abbad51c72b7cbc94cb6a7a7e3d883d128c35f0 Mon Sep 17 00:00:00 2001
From: Botond Ballo <botond@mozilla.com>
Date: Mon, 4 Dec 2023 01:51:12 +0000
Subject: [PATCH] Bug 1846935 - Use FuzzyEqualsCoordinate in the computation of
 userScrolled. r=hiro

Differential Revision: https://phabricator.services.mozilla.com/D193393
---
 gfx/layers/apz/src/AsyncPanZoomController.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp
index 5ae39a4ec476..c49735f652da 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -5314,10 +5314,11 @@ void AsyncPanZoomController::NotifyLayersUpdated(
   // XXX Suspicious comparison between layout and visual scroll offsets.
   // This may not do the right thing when we're zoomed in.
   CSSPoint lastScrollOffset = mLastContentPaintMetrics.GetLayoutScrollOffset();
-  bool userScrolled = !FuzzyEqualsAdditive(Metrics().GetVisualScrollOffset().x,
-                                           lastScrollOffset.x) ||
-                      !FuzzyEqualsAdditive(Metrics().GetVisualScrollOffset().y,
-                                           lastScrollOffset.y);
+  bool userScrolled =
+      !FuzzyEqualsCoordinate(Metrics().GetVisualScrollOffset().x,
+                             lastScrollOffset.x) ||
+      !FuzzyEqualsCoordinate(Metrics().GetVisualScrollOffset().y,
+                             lastScrollOffset.y);
 
   if (aScrollMetadata.DidContentGetPainted()) {
     mLastContentPaintMetadata = aScrollMetadata;