Remove support for the externalResourcesRequired attribute.

LayoutTests/svg/custom/svg2-loadevents-capturing.svg

Index: LayoutTests/svg/custom/svg2-loadevents-capturing.svg
diff --git a/LayoutTests/svg/custom/loadevents-capturing.svg b/LayoutTests/svg/custom/svg2-loadevents-capturing.svg
similarity index 81%
rename from LayoutTests/svg/custom/loadevents-capturing.svg
rename to LayoutTests/svg/custom/svg2-loadevents-capturing.svg
index 14b806f7f38bc8ff1a81aa3c6d7cc7196c2def77..93eced7cd3e8c45b52ab6224cd29944d0d3be34f 100644
--- a/LayoutTests/svg/custom/loadevents-capturing.svg
+++ b/LayoutTests/svg/custom/svg2-loadevents-capturing.svg
@@ -14,7 +14,7 @@
       function reportResults()
       {
         var console = document.getElementById("console");
-        var expected = [ "image", "text", "text", "text", "g", "svg" ];
+        var expected = [ "image", "svg" ];
         for (var i = 0; i < expected.length; ++i) {
             if (results[i] != expected[i]) {
               console.appendChild(document.createTextNode("FAIL: " + i + " should be " + expected[i] + " but instead is " + results[i] + ".\n"));
@@ -27,9 +27,9 @@
     ]]>
   </script>
   <g>
-    <image externalResourcesRequired="false" id="image" width="100" height="100" xlink:href="resources/green-checker.png" />
+    <image id="image" width="100" height="100" xlink:href="resources/green-checker.png" />
     <text y="130" x="20">This tests that load dispatching works when there are no</text>
-    <text y="150" x="20">direct listeners, but there are capturing event listeners on an ancestor. Bug 16447</text>
+    <text y="150" x="20">direct listeners, but there are capturing event listeners on an ancestor.</text>
     <text y="170" x="20" id="console" />
   </g>
 </svg>