Fix scroll_sensitivity related naming issue (#35462)

Signed-off-by: Euclid Ye <yezhizhenjiakang@gmail.com>

components/layout_thread_2020/lib.rs

@@ -854,7 +854,7 @@ impl LayoutThread {
             fragment_tree.scrollable_overflow(),
             self.id.into(),
             epoch.into(),
-            fragment_tree.root_scroll_sensitivity,
+            fragment_tree.viewport_scroll_sensitivity,
         );
         display_list.wr.begin();