Bug 616516 - Try to fix few pixel intermittent animation reftest failure by using crispEdge drawing. r=dholbert

layout/reftests/svg/smil/anim-rect-rxry-1-ref.svg

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<svg xmlns="http://www.w3.org/2000/svg">
+<svg xmlns="http://www.w3.org/2000/svg" shape-rendering="crispEdges">
   <g fill="blue" stroke="red" stroke-width="10" transform="translate(10 10)">
     <!-- Squares -->
     <rect x="0" width="40" height="40"/>

layout/reftests/svg/smil/anim-rect-rxry-1.svg

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <svg xmlns="http://www.w3.org/2000/svg"
      xmlns:xlink="http://www.w3.org/1999/xlink"
-     class="reftest-wait">
+     class="reftest-wait"  shape-rendering="crispEdges">
   <g fill="blue" stroke="red" stroke-width="10" transform="translate(10 10)">
     <!-- Squares -->
     <rect x="0" width="40" height="40"/>