Bug 746632 - If no fallback colour is specified we shouldn't draw anything when the URL fails to resolve. r=dbaron

layout/reftests/svg/fallback-color-02-ref.svg

@@ -8,5 +8,5 @@
 
 <!-- From https://bugzilla.mozilla.org/show_bug.cgi?id=368840 -->
 
-	<rect x="0%" y="0%" width="100%" height="100%" fill="black"/>
+	<rect x="0%" y="0%" width="100%" height="100%" fill="white"/>
 </svg>

layout/style/nsCSSParser.cpp

@@ -9266,7 +9266,7 @@ CSSParserImpl::ParsePaint(nsCSSProperty aPropID)
     return false;
   if (x.GetUnit() == eCSSUnit_URL) {
     if (!ParseVariant(y, VARIANT_COLOR | VARIANT_NONE, nsnull))
-      y.SetColorValue(NS_RGB(0, 0, 0));
+      y.SetNoneValue();
   }
   if (!ExpectEndProperty())
     return false;