Update most LayoutTests to be agnostic to scrollTopLeftInterop mode

LayoutTests/fast/events/resources/drag-and-drop-autoscroll-frame.js

 function $(id) { return document.getElementById(id); }
 
 var lastScrollLeft;
 var lastScrollTop;
 window.onload = function() {
     var draggable = $('draggable');
     var sample = $('sample');
     var scrollBarWidth = $('scrollbars').offsetWidth - $('scrollbars').firstChild.offsetWidth;
     var scrollBarHeight = $('scrollbars').offsetHeight - $('scrollbars').firstChild.offsetHeight;
     var eastX = window.innerWidth - scrollBarWidth - 10;
     var northY = 10;
     var southY= window.innerHeight - scrollBarHeight - 10;
     var westX = 10;
 
     function moveTo(newState, x, y)
     {
         state = newState;
-        lastScrollLeft = document.body.scrollLeft;
-        lastScrollTop = document.body.scrollTop;
+        lastScrollLeft = document.scrollingElement.scrollLeft;
+        lastScrollTop = document.scrollingElement.scrollTop;
         eventSender.mouseMoveTo(x, y);
     }
 
     var state = 'START';
     function process(event)
     {
         debug('state=' + state);
         switch (state) {
         case 'NE':
-            shouldBeTrue('document.body.scrollLeft > 0');
-            shouldBeTrue('!document.body.scrollTop');
+            shouldBeTrue('document.scrollingElement.scrollLeft > 0');
+            shouldBeTrue('!document.scrollingElement.scrollTop');
             moveTo('SE', westX, southY);
             break;
         case 'SE':
-            shouldBeTrue('document.body.scrollLeft > 0');
-            shouldBeTrue('document.body.scrollTop > 0');
+            shouldBeTrue('document.scrollingElement.scrollLeft > 0');
+            shouldBeTrue('document.scrollingElement.scrollTop > 0');
             moveTo('SW', westX, southY);
             break;
         case 'SW':
-            shouldBeTrue('document.body.scrollLeft < lastScrollLeft');
-            shouldBeTrue('document.body.scrollTop > 0');
+            shouldBeTrue('document.scrollingElement.scrollLeft < lastScrollLeft');
+            shouldBeTrue('document.scrollingElement.scrollTop > 0');
             moveTo('NW', westX, northY);
             break;
         case 'NW':
-            shouldBeTrue('document.body.scrollLeft <= lastScrollLeft');
-            shouldBeTrue('document.body.scrollTop < lastScrollTop');
+            shouldBeTrue('document.scrollingElement.scrollLeft <= lastScrollLeft');
+            shouldBeTrue('document.scrollingElement.scrollTop < lastScrollTop');
             eventSender.mouseUp();
             $('container').outerHTML = '';
             if (window.parent !== window)
                 window.jsTestIsAsync = false;
             finishJSTest();
             if (!window.jsTestIsAsync)
                 window.parent.postMessage($('console').innerHTML, '*');
             state = 'DONE';
             break;
         case 'DONE':
@@ skipping 12 matching lines @@
 
     eventSender.dragMode = false;
 
     // Grab draggable
     eventSender.mouseMoveTo(draggable.offsetLeft + 5, draggable.offsetTop + 5);
     eventSender.mouseDown();
 
     window.onscroll = process;
     process();
 };