Fix for IE

Author: sjdweb

app/azureBlobUploadWorker.js

@@ -1,3 +1,26 @@
+(function(){
+ 
+  if ("performance" in self === false) {
+      self.performance = {};
+  }
+  
+  Date.now = (Date.now || function () {  // thanks IE8
+      return new Date().getTime();
+  });
+ 
+  if ("now" in self.performance === false) {
+    var nowOffset = Date.now();
+    
+    if (performance.timing && performance.timing.navigationStart) {
+      nowOffset = performance.timing.navigationStart;
+    }
+ 
+    self.performance.now = function now() {
+      return Date.now() - nowOffset;
+    };
+  }
+})();
+
 (function () {
     var arrayBufferUtils = (function() {
         function arraybuffer2WordArray(arrayBuffer) {