Draggable Tests: fix IE scroll tests affected by focus issues.

Calling element.focus() causes scroll in IE. In order to correctly test scroll behavior,
we must calculate scrollTop on the drag event, before .focus is called.

Author: mikesherov

tests/unit/draggable/draggable_options.js

@@ -835,7 +835,8 @@ test( "scroll, scrollSensitivity, and scrollSpeed", function() {
 
 	TestHelpers.draggable.setScrollable( "#main", false );
 
-	var viewportHeight = $( window ).height(),
+	var currentScrollTop,
+		viewportHeight = $( window ).height(),
 		element = $( "#draggable1" ).draggable({ scroll: true }).appendTo( "#qunit-fixture" ),
 		scrollSensitivity = element.draggable( "option", "scrollSensitivity" ),
 		scrollSpeed = element.draggable( "option", "scrollSpeed" );
@@ -845,29 +846,35 @@ test( "scroll, scrollSensitivity, and scrollSpeed", function() {
 		left: 1
 	});
 
+	$( element ).one( "drag", function() {
+		equal( $( window ).scrollTop(), 0, "scroll: true doesn't scroll when the element is dragged outside of scrollSensitivity" );
+	});
+
 	element.simulate( "drag", {
 		dx: 1,
 		y: viewportHeight - scrollSensitivity - 1,
 		moves: 1
 	});
 
-	ok( $( window ).scrollTop() === 0, "scroll: true doesn't scroll when the element is dragged outside of scrollSensitivity" );
-
 	element.draggable( "option", "scrollSensitivity", scrollSensitivity + 10 );
 
 	element.offset({
 		top: viewportHeight - scrollSensitivity - 1,
 		left: 1
 	});
 
+	currentScrollTop = $( window ).scrollTop();
+
+	$( element ).one( "drag", function() {
+		ok( $( window ).scrollTop() - currentScrollTop, scrollSpeed, "scroll: true scrolls when the element is dragged within scrollSensitivity" );
+	});
+
 	element.simulate( "drag", {
 		dx: 1,
 		y: viewportHeight - scrollSensitivity - 1,
 		moves: 1
 	});
 
-	ok( $( window ).scrollTop() === scrollSpeed, "scroll: true scrolls when the element is dragged within scrollSensitivity" );
-
 	TestHelpers.draggable.restoreScroll( document );
 });