Bug 1149516 - draw continuous stroke if stroke-dasharray = 0. r=jwatt

dom/svg/SVGContentUtils.cpp

@@ -144,9 +144,6 @@ GetStrokeDashData(SVGContentUtils::AutoStrokeOptions* aStrokeOptions,
   // stroke to essentially be continuous or to be nonexistent in which case
   // we can avoid expensive stroking operations (the underlying platform
   // graphics libraries don't seem to optimize for this).
-  if (totalLengthOfDashes <= 0 && totalLengthOfGaps <= 0) {
-    return eNoStroke;
-  }
   if (totalLengthOfGaps <= 0) {
     return eContinuousStroke;
   }

layout/reftests/svg/stroke-linecap-round-w-zero-length-segs-01.svg

@@ -152,4 +152,10 @@ path.coverer {
     <circle cy="80" r="8"/>
     <path class="circles-expected" d="M0,0v81" stroke-dasharray="0 40" />
   </g>
+  <g transform="translate(575,25)">
+    <circle cy="0" r="8"/>
+    <circle cy="40" r="8"/>
+    <circle cy="80" r="8"/>
+    <path class="circles-expected" d="M0,0v81" stroke-dasharray="0" />
+  </g>
 </svg>