Fix bug in reftest (the binding should create an anonymous rect, it's only the gradient reference that should fail)

layout/reftests/svg/moz-only/pass-black.svg

@@ -0,0 +1,8 @@
+<!--
+     Any copyright is dedicated to the Public Domain.
+     http://creativecommons.org/licenses/publicdomain/
+-->
+<svg xmlns="http://www.w3.org/2000/svg" version="1.1">
+  <title>Testcase reference file for black pass condition</title>
+  <rect width="100%" height="100%" fill="black"/>
+</svg>

layout/reftests/svg/moz-only/reftest.list

@@ -4,6 +4,6 @@
 == xbl-grad-ref--grad-in-binding-01.svg         pass.svg
 == xbl-grad-ref--grad-in-binding-02.svg         pass.svg
 == xbl-grad-ref--grad-in-bound-01.svg           pass.svg
-fails == xbl-grad-ref--grad-in-bound-02.svg     pass.svg
+fails == xbl-grad-ref--grad-in-bound-02.svg     pass-black.svg
 fails == xbl-grad-ref--grad-in-resources-01.svg pass.svg
 fails == xbl-grad-ref--grad-in-resources-02.svg pass.svg

layout/reftests/svg/moz-only/xbl-grad-ref--grad-in-bound-02.svg

@@ -14,6 +14,6 @@
     <stop stop-color="red"/>
   </linearGradient>
 
-  <rect width="100%" height="100%" fill="lime"/>
+  <rect width="100%" height="100%" fill="red"/>
 
 </svg>