Return an absolute URL for HTMLImageElement.currentSrc

LayoutTests/fast/dom/HTMLImageElement/resources/currentSrcHelper.js

Index: LayoutTests/fast/dom/HTMLImageElement/resources/currentSrcHelper.js
diff --git a/LayoutTests/fast/dom/HTMLImageElement/resources/currentSrcHelper.js b/LayoutTests/fast/dom/HTMLImageElement/resources/currentSrcHelper.js
new file mode 100644
index 0000000000000000000000000000000000000000..b54e14bf691591cf33461053c72b1d5f11cbdb06
--- /dev/null
+++ b/LayoutTests/fast/dom/HTMLImageElement/resources/currentSrcHelper.js
@@ -0,0 +1,9 @@
+function fileName(src) {
+    var array = src.split('/');
+    return array[array.length -1];
+};
+
+function currentSrcFileName(id) {
+    var currentSrc = document.getElementById(id).currentSrc;
+    return fileName(currentSrc);
+};