Bug 1631518 - Don't treat overflow:hidden divs as scrollframes for to…

…uch-action purposes with WR enabled. r=tnikkel

Depends on D75143

Differential Revision: https://phabricator.services.mozilla.com/D75144

layout/generic/nsFrame.cpp

@@ -11591,16 +11591,20 @@ CompositorHitTestInfo nsIFrame::GetCompositorHitTestInfo(
     nsIFrame* touchActionFrame = this;
     if (nsIScrollableFrame* scrollFrame =
             nsLayoutUtils::GetScrollableFrameFor(this)) {
-      touchActionFrame = do_QueryFrame(scrollFrame);
-      // On scrollframes, stop inheriting the pan-x and pan-y flags; instead,
-      // reset them back to zero to allow panning on the scrollframe unless we
-      // encounter an element that disables it that's inside the scrollframe.
-      // This is equivalent to the |considerPanning| variable in
-      // TouchActionHelper.cpp, but for a top-down traversal.
-      CompositorHitTestInfo panMask(
-          CompositorHitTestFlags::eTouchActionPanXDisabled,
-          CompositorHitTestFlags::eTouchActionPanYDisabled);
-      inheritedTouchAction -= panMask;
+      ScrollStyles ss = scrollFrame->GetScrollStyles();
+      if (ss.mVertical != StyleOverflow::Hidden ||
+          ss.mHorizontal != StyleOverflow::Hidden) {
+        touchActionFrame = do_QueryFrame(scrollFrame);
+        // On scrollframes, stop inheriting the pan-x and pan-y flags; instead,
+        // reset them back to zero to allow panning on the scrollframe unless we
+        // encounter an element that disables it that's inside the scrollframe.
+        // This is equivalent to the |considerPanning| variable in
+        // TouchActionHelper.cpp, but for a top-down traversal.
+        CompositorHitTestInfo panMask(
+            CompositorHitTestFlags::eTouchActionPanXDisabled,
+            CompositorHitTestFlags::eTouchActionPanYDisabled);
+        inheritedTouchAction -= panMask;
+      }
     }
 
     result += inheritedTouchAction;