The cssHook from addGetHookIf wasn't actually getting added

src/css.js

@@ -370,7 +370,7 @@ jQuery.each([ "height", "width" ], function( i, name ) {
 });
 
 // Support: Android 2.3
-addGetHookIf( jQuery.cssHooks.marginRight, support.reliableMarginRight,
+jQuery.cssHooks.marginRight = addGetHookIf( support.reliableMarginRight,
 	function ( elem, computed ) {
 		if ( computed ) {
 			// WebKit Bug 13343 - getComputedStyle returns wrong value for margin-right

src/css/addGetHookIf.js

-define( function() {
+define(function() {
 
-function addGetHookIf( hookVar, conditionFn, hookFn ) {
+function addGetHookIf( conditionFn, hookFn ) {
 	// Define the hook, we'll check on the first run if it's really needed.
-	hookVar = {
+	return {
 		get: function() {
 			var condition = conditionFn();
 
@@ -16,14 +16,13 @@ function addGetHookIf( hookVar, conditionFn, hookFn ) {
 				// Hook not needed (or it's not possible to use it due to missing dependency),
 				// remove it.
 				// Since there are no other hooks for marginRight, remove the whole object.
-				delete hookVar.get;
+				delete this.get;
 				return;
 			}
 
 			// Hook needed; redefine it so that the support test is not executed again.
-			hookVar.get = hookFn;
 
-			return hookVar.get.apply( hookVar, arguments );
+			return (this.get = hookFn).apply( hookVar, arguments );
 		}
 	};
 }

src/offset.js

@@ -187,7 +187,7 @@ jQuery.each( {scrollLeft: "pageXOffset", scrollTop: "pageYOffset"}, function( me
 // getComputedStyle returns percent when specified for top/left/bottom/right
 // rather than make the css module depend on the offset module, we just check for it here
 jQuery.each( [ "top", "left" ], function( i, prop ) {
-	addGetHookIf( jQuery.cssHooks[ prop ], support.pixelPosition,
+	jQuery.cssHooks[ prop ] = addGetHookIf( support.pixelPosition,
 		function ( elem, computed ) {
 			if ( computed ) {
 				computed = curCSS( elem, prop );