convert segmentXHR to use xhr helper

@@ -639,31 +639,24 @@ var
       }
 
       // request the next segment
-      segmentXhr = new window.XMLHttpRequest();
-      segmentXhr.open('GET', segmentUri);
-      segmentXhr.responseType = 'arraybuffer';
-      segmentXhr.onreadystatechange = function() {
-        // wait until the request completes
-        if (this.readyState !== 4) {
-          return;
-        }
-
+      segmentXhr = xhr({
+        url: segmentUri,
+        responseType: 'arraybuffer'
+      }, function(error, url) {
         // the segment request is no longer outstanding
         segmentXhr = null;
 
-        // trigger an error if the request was not successful
-        if (this.status >= 400) {
+        if (error) {
           player.hls.error = {
             status: this.status,
-            message: 'HLS segment request error at URL: ' + segmentUri,
+            message: 'HLS segment request error at URL: ' + url,
             code: (this.status >= 500) ? 4 : 2
           };
 
           // try moving on to the next segment
           player.hls.mediaIndex++;
           return;
-        }
-
+        } else {
           // stop processing if the request was aborted
           if (!this.response) {
             return;
@@ -698,9 +691,10 @@ var
           // figure out what stream the next segment should be downloaded from
           // with the updated bandwidth information
           updateCurrentPlaylist();
-      };
+        }
+      });
+
       startTime = +new Date();
-      segmentXhr.send(null);
     };
 
     // load the MediaSource into the player