Revert "Offset: account for scroll when calculating position"

This reverts commit 2d71594.

This commit provoked new issues: jquerygh-2836, jquerygh-2828.

At the meeting, we decided to revert offending commit
(in all three branches - 2.2-stable, 1.12-stable and master)
and tackle this issue in 3.x.

Fixes jquerygh-2828

src/offset.js

@@ -144,11 +144,8 @@ jQuery.fn.extend( {
 			}
 
 			// Add offsetParent borders
-			// Subtract offsetParent scroll positions
-			parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true ) -
-				offsetParent.scrollTop();
-			parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true ) -
-				offsetParent.scrollLeft();
+			parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true );
+			parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true );
 		}
 
 		// Subtract parent offsets and element margins

test/unit/offset.js

@@ -406,7 +406,7 @@ testIframe( "offset/table", "table", function( $, window, document, assert ) {
 } );
 
 testIframe( "offset/scroll", "scroll", function( $, win, doc, assert ) {
-	assert.expect( 30 );
+	assert.expect( 24 );
 
 	assert.equal( $( "#scroll-1" ).offset().top, 7, "jQuery('#scroll-1').offset().top" );
 	assert.equal( $( "#scroll-1" ).offset().left, 7, "jQuery('#scroll-1').offset().left" );
@@ -462,17 +462,6 @@ testIframe( "offset/scroll", "scroll", function( $, win, doc, assert ) {
 	assert.notEqual( $().scrollLeft( null ), null, "jQuery().scrollLeft(null) testing setter on empty jquery object" );
 	assert.strictEqual( $().scrollTop(), undefined, "jQuery().scrollTop() testing getter on empty jquery object" );
 	assert.strictEqual( $().scrollLeft(), undefined, "jQuery().scrollLeft() testing getter on empty jquery object" );
-
-	// Tests position after parent scrolling (#15239)
-	$( "#scroll-1" ).scrollTop( 0 );
-	$( "#scroll-1" ).scrollLeft( 0 );
-	assert.equal( $( "#scroll-1-1" ).position().top, 6, "jQuery('#scroll-1-1').position().top unaffected by parent scrolling" );
-	assert.equal( $( "#scroll-1-1" ).position().left, 6, "jQuery('#scroll-1-1').position().left unaffected by parent scrolling" );
-
-	$( "#scroll-1" ).scrollTop( 5 );
-	$( "#scroll-1" ).scrollLeft( 5 );
-	assert.equal( $( "#scroll-1-1" ).position().top, 6, "jQuery('#scroll-1-1').position().top unaffected by parent scrolling" );
-	assert.equal( $( "#scroll-1-1" ).position().left, 6, "jQuery('#scroll-1-1').position().left unaffected by parent scrolling" );
 } );
 
 testIframe( "offset/body", "body", function( $, window, document, assert ) {
@@ -486,6 +475,7 @@ testIframe( "offset/body", "body", function( $, window, document, assert ) {
 
 QUnit.test( "chaining", function( assert ) {
 	assert.expect( 3 );
+
 	var coords = { "top":  1, "left":  1 };
 	assert.equal( jQuery( "#absolute-1" ).offset( coords ).jquery, jQuery.fn.jquery, "offset(coords) returns jQuery object" );
 	assert.equal( jQuery( "#non-existent" ).offset( coords ).jquery, jQuery.fn.jquery, "offset(coords) with empty jQuery set returns jQuery object" );