Bug 695677: Add <use> element to svg-image-script-2.svg, to force its resources file to load before onload fires. r=longsonr

layout/reftests/svg/as-image/script100x100.svg

@@ -1,6 +1,10 @@
 <svg xmlns="http://www.w3.org/2000/svg" version="1.1"
      width="100" height="100">
   <defs>
+    <!-- So that other documents can svg:use this one and force it to
+         load before onload -->
+    <g id="empty" />
+
     <pattern id="p1" patternUnits="userSpaceOnUse" width="100%" height="100%">
       <rect width="100%" height="100%" fill="lime"/>
       <rect id="r1" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Script" width="100%" height="100%" fill="orange"/>

layout/reftests/svg/as-image/svg-image-script-2.svg

@@ -1,6 +1,10 @@
 <svg xmlns="http://www.w3.org/2000/svg"
      xmlns:xlink="http://www.w3.org/1999/xlink"
      width="100" height="100" class="reftest-wait">
+
+  <!-- This <use> just forces our resources file to load before onload fires -->
+  <use xlink:href="script100x100.svg#empty" />
+
   <rect width="100%" height="100%" fill="red"/>
   <rect width="100%" height="100%" fill="url(script100x100.svg#p1)"/>
   <rect id="r1" width="100%" height="100%" fill="transparent"/>