Make sure <url>s are being serialized according to spec

LayoutTests/fast/css/cursor-parsing-image-set.html

Index: LayoutTests/fast/css/cursor-parsing-image-set.html
diff --git a/LayoutTests/fast/css/cursor-parsing-image-set.html b/LayoutTests/fast/css/cursor-parsing-image-set.html
index c74de4d812a202e2b93f76691bdfe26892e1879e..d9374b50a9921e7d8edf71121b8314ee01d0b712 100644
--- a/LayoutTests/fast/css/cursor-parsing-image-set.html
+++ b/LayoutTests/fast/css/cursor-parsing-image-set.html
@@ -15,10 +15,10 @@ function makeCursorRule(rule)
     return "cursor: " + rule + ";";
 }
 
-function testCursorRule(rule)
+function testCursorRule(rule, expected)
 {
     var cssText = makeCursorRule(rule);
-    shouldBeEqualToString('roundtripCssRule("' + cssText + '")', cssText);
+    shouldBeEqualToString('roundtripCssRule("' + cssText + '")', makeCursorRule(expected));
 }
 
 function roundtripCssRule(cssText)
@@ -36,10 +36,10 @@ function roundtripCssRule(cssText)
 // to avoid triggering any network activity.
 
 debug('Test a bunch of cursor rules which should round-trip exactly.');
-testCursorRule('-webkit-image-set(url(file:///foo.png) 1x), auto');
-testCursorRule('-webkit-image-set(url(file:///foo.png) 1x, url(file:///foo2x.png) 2x), auto');
-testCursorRule('-webkit-image-set(url(file:///foo.png) 1x, url(file:///foo2x.png) 2x) 2 3, auto');
-testCursorRule('-webkit-image-set(url(file:///foo03.png) 0.3x, url(file:///foo5x.png) 5x) 6 5, url(file:///foo.png) 12 3, pointer');
+testCursorRule('-webkit-image-set(url(file:///foo.png) 1x), auto', '-webkit-image-set(url("file:///foo.png") 1x), auto');
+testCursorRule('-webkit-image-set(url(file:///foo.png) 1x, url(file:///foo2x.png) 2x), auto', '-webkit-image-set(url("file:///foo.png") 1x, url("file:///foo2x.png") 2x), auto');
+testCursorRule('-webkit-image-set(url(file:///foo.png) 1x, url(file:///foo2x.png) 2x) 2 3, auto', '-webkit-image-set(url("file:///foo.png") 1x, url("file:///foo2x.png") 2x) 2 3, auto');
+testCursorRule('-webkit-image-set(url(file:///foo03.png) 0.3x, url(file:///foo5x.png) 5x) 6 5, url(file:///foo.png) 12 3, pointer', '-webkit-image-set(url("file:///foo03.png") 0.3x, url("file:///foo5x.png") 5x) 6 5, url("file:///foo.png") 12 3, pointer');
 
 successfullyParsed = true;
 </script>