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

LayoutTests/fast/backgrounds/script-tests/multiple-backgrounds-computed-style.js

Index: LayoutTests/fast/backgrounds/script-tests/multiple-backgrounds-computed-style.js
diff --git a/LayoutTests/fast/backgrounds/script-tests/multiple-backgrounds-computed-style.js b/LayoutTests/fast/backgrounds/script-tests/multiple-backgrounds-computed-style.js
index 807b30799297e392e6f925f63132183a57a7b96f..8250c7b07a29ad6b8619008c96fafe222a01c8d8 100644
--- a/LayoutTests/fast/backgrounds/script-tests/multiple-backgrounds-computed-style.js
+++ b/LayoutTests/fast/backgrounds/script-tests/multiple-backgrounds-computed-style.js
@@ -13,12 +13,12 @@ function test(property, value)
 
 // shorthands
 shouldBe('test("backgroundImage", "background: none 10px 10px, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC) 20px 20px;")',
-  '"none, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC)"');
+  '"none, url(\\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC\\")"');
 shouldBe('test("backgroundPosition", "background: none 10px 10px, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC) 20px 20px;")', '"10px 10px, 20px 20px"');
 
 // background longhands
 shouldBe('test("backgroundImage", "background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC), none, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC)")',
-  '"url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC), none, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC)"');
+  '"url(\\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC\\"), none, url(\\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC\\")"');
 shouldBe('test("backgroundRepeat", "background-image: none, none, none, none; background-repeat: repeat-x, repeat-y, repeat, no-repeat;")', '"repeat-x, repeat-y, repeat, no-repeat"');
 shouldBe('test("backgroundSize", "background-image: none, none, none; background-size: contain, cover, 20px 10%;")', '"contain, cover, 20px 10%"');
 shouldBe('test("webkitBackgroundSize", "background-image: none, none, none; -webkit-background-size: contain, cover, 20px 10%;")', '"contain, cover, 20px 10%"');
@@ -33,7 +33,7 @@ shouldBe('test("backgroundPositionX", "background-image: none, none, none, none,
 shouldBe('test("backgroundPositionY", "background-image: none, none, none, none, none; background-position-y: 20px, 10%, bottom, top, center;")', '"20px, 10%, 100%, 0%, 50%"');
 
 // mask shorthands
-shouldBe('test("webkitMaskImage", "-webkit-mask: none 10px 10px, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC) 20px 20px;")', '"none, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC)"');
+shouldBe('test("webkitMaskImage", "-webkit-mask: none 10px 10px, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC) 20px 20px;")', '"none, url(\\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC\\")"');
 shouldBe('test("webkitMaskPosition", "-webkit-mask: none 10px 10px, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC) 20px 20px;")', '"10px 10px, 20px 20px"');
 shouldBe('test("webkitMaskClip", "-webkit-mask: center url() content-box ")', '"content-box"');
 shouldBe('test("webkitMaskClip", "-webkit-mask: content-box padding-box")', '"padding-box"');
@@ -41,7 +41,7 @@ shouldBe('test("webkitMaskClip", "-webkit-mask: border-box url() content-box")',
 shouldBe('test("webkitMaskClip", "-webkit-mask: url() repeat-x content-box border-box scroll ")', '"border-box"');
 
 // mask longhands
-shouldBe('test("webkitMaskImage", "-webkit-mask-image: none, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC);")', '"none, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC)"');
+shouldBe('test("webkitMaskImage", "-webkit-mask-image: none, url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC);")', '"none, url(\\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAIAAACQd1PeAAAADElEQVR42mP4%2F58BAAT%2FAf9jgNErAAAAAElFTkSuQmCC\\")"');
 shouldBe('test("webkitMaskSize", "-webkit-mask-image: none, none, none; -webkit-mask-size: contain, cover, 20px 10%;")', '"contain, cover, 20px 10%"');
 shouldBe('test("webkitMaskRepeat", "-webkit-mask-image: none, none, none, none; -webkit-mask-repeat: repeat-x, repeat-y, repeat, no-repeat;")', '"repeat-x, repeat-y, repeat, no-repeat"');
 shouldBe('test("webkitMaskClip", "-webkit-mask-image: none, none; -webkit-mask-clip: border-box, padding-box;")', '"border-box, padding-box"');