ScrollTopLeftInterop should not be marked experimental

LayoutTests/fast/css/zoom-body-scroll.html

Index: LayoutTests/fast/css/zoom-body-scroll.html
diff --git a/LayoutTests/fast/css/zoom-body-scroll.html b/LayoutTests/fast/css/zoom-body-scroll.html
index 99a139e9b06d535d09d2362c6a14cef6e1e6dc5b..9f5c405ba9a9bffc29dba0eef8128743552132d2 100644
--- a/LayoutTests/fast/css/zoom-body-scroll.html
+++ b/LayoutTests/fast/css/zoom-body-scroll.html
@@ -25,24 +25,24 @@
             checkValue('document.body.scrollWidth', 1000);
 
             // Scrolling right to 50.
-            documentElement.scrollLeft = 50;
-            checkValue('document.documentElement.scrollLeft', 50);
+            body.scrollLeft = 50;
+            checkValue('document.body.scrollLeft', 50);
 
             // Zooming in.
             eventSender.zoomPageIn();
             checkValue('document.body.scrollHeight', 1000);
             checkValue('document.body.scrollWidth', 1000);
-            checkValue('document.documentElement.scrollTop', 0);
-            checkValue('document.documentElement.scrollLeft', 50);
+            checkValue('document.body.scrollTop', 0);
+            checkValue('document.body.scrollLeft', 50);
 
             // Scrolling down to 100.
-            documentElement.scrollTop = 100;
-            checkValue('document.documentElement.scrollTop', 100);
+            body.scrollTop = 100;
+            checkValue('document.body.scrollTop', 100);
 
             // Zooming back out.
             eventSender.zoomPageOut();
-            checkValue('document.documentElement.scrollTop', 100);
-            checkValue('document.documentElement.scrollLeft', 50);
+            checkValue('document.body.scrollTop', 100);
+            checkValue('document.body.scrollLeft', 50);
         }
     </script>
 </body>