Update most LayoutTests to be agnostic to scrollTopLeftInterop mode

LayoutTests/compositing/rtl/rtl-absolute-overflow-scrolled.html

Index: LayoutTests/compositing/rtl/rtl-absolute-overflow-scrolled.html
diff --git a/LayoutTests/compositing/rtl/rtl-absolute-overflow-scrolled.html b/LayoutTests/compositing/rtl/rtl-absolute-overflow-scrolled.html
index 05809f1466ad29c889cebfcd5f0fe134d9afdb91..561201d31563261573dc8bdd4ca951be3cd7c08a 100644
--- a/LayoutTests/compositing/rtl/rtl-absolute-overflow-scrolled.html
+++ b/LayoutTests/compositing/rtl/rtl-absolute-overflow-scrolled.html
@@ -44,7 +44,7 @@
         }
 
         // The far left coordinate of the document varies by window width.
-        var offset = document.body.clientWidth - document.body.scrollWidth + 1;
+        var offset = document.body.clientWidth - document.scrollingElement.scrollWidth + 1;
         document.getElementById('layer').style.left = offset + 50;
         document.getElementById('indicator').style.left = offset + 50;