Update most LayoutTests to be agnostic to scrollTopLeftInterop mode

LayoutTests/fast/forms/resources/common.js

Index: LayoutTests/fast/forms/resources/common.js
diff --git a/LayoutTests/fast/forms/resources/common.js b/LayoutTests/fast/forms/resources/common.js
index ca3a27803d64791bb3069a2a4ff096312d160b10..fe91761abd33b6db994f1d82d6739a3303da8add 100644
--- a/LayoutTests/fast/forms/resources/common.js
+++ b/LayoutTests/fast/forms/resources/common.js
@@ -88,10 +88,10 @@ function createFormControlDataSet() {
 
 function getAbsoluteRect(element) {
     var rect = element.getBoundingClientRect();
-    rect.top += document.body.scrollTop;
-    rect.bottom += document.body.scrollTop;
-    rect.left += document.body.scrollLeft;
-    rect.right += document.body.scrollLeft;
+    rect.top += document.scrollingElement.scrollTop;
+    rect.bottom += document.scrollingElement.scrollTop;
+    rect.left += document.scrollingElement.scrollLeft;
+    rect.right += document.scrollingElement.scrollLeft;
     return rect;
 }