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

third_party/WebKit/Source/core/css/CSSMarkup.cpp

Index: third_party/WebKit/Source/core/css/CSSMarkup.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSMarkup.cpp b/third_party/WebKit/Source/core/css/CSSMarkup.cpp
index c9945a2f527cfe71d92db131bd68255a5820ef6f..7c5e890579db48b3c997dffb425a2d0530aeaaf0 100644
--- a/third_party/WebKit/Source/core/css/CSSMarkup.cpp
+++ b/third_party/WebKit/Source/core/css/CSSMarkup.cpp
@@ -263,21 +263,9 @@ String serializeString(const String& string)
     return builder.toString();
 }
 
-String serializeStringWithoutQuotations(const String& string)
+String serializeURI(const String& string)
 {
-    StringBuilder appendTo;
-    unsigned index = 0;
-    while (index < string.length()) {
-        UChar32 c = string.characterStartingAt(index);
-        index += U16_LENGTH(c);
-        if (c <= 0x1f)
-            serializeCharacterAsCodePoint(c, appendTo);
-        else if (c == 0x22 || c == 0x5c)
-            serializeCharacter(c, appendTo);
-        else
-            appendTo.append(c);
-    }
-    return appendTo.toString();
+    return "url(" + serializeString(string) + ")";
 }
 
 } // namespace blink