diff -r 000000000000 -r 6474c204b198 dom/workers/test/fileReadSlice_worker.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/workers/test/fileReadSlice_worker.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,16 @@
+/**
+ * Expects an object containing a blob, a start index and an end index
+ * for slicing. Returns the contents of the blob read as text.
+ */
+onmessage = function(event) {
+  var blob = event.data.blob;
+  var start = event.data.start;
+  var end = event.data.end;
+
+  var slicedBlob = blob.slice(start, end);
+
+  var fileReader = new FileReaderSync();
+  var text = fileReader.readAsText(slicedBlob);
+
+  postMessage(text);
+};