title: Google Chrome for IOS 6 ajax file uploading progress event doesn't work
body: <p>I have a problem with  xmlhttprequest file uploading progress event on Google Chrome for ios6. code already work on all desktop browsers and Safari(ios 6). 
  also there is a problem wiht uploading  mov files in google chrome (ios 6), when trying to upload I get file size = 0.
  Is there any solution for it ?</p>
  
  <p>this is part of my code</p>
  
  <pre><code>var xhr = new XMLHttpRequest();
  var eventSource = xhr.upload;
  
  xhr.addEventListener("load", this.onUploadComplete(uploadInfo));
  xhr.addEventListener("error", this.onUploadError(uploadInfo));
  xhr.addEventListener("abort", this.onUploadAbort(uploadInfo));
  
  // changing Url  for preventing ajax call caching( Android , IOS 6)
  var ts = Date.now(), rquery = /\?/, rts = /([?&amp;])_=[^&amp;]*/,
  ret = uploadUrl.replace( rts, "$1_=" + ts );
  uploadUrl = ret + ( ( ret === uploadUrl ) ? ( rquery.test( uploadUrl ) ? "&amp;" : "?" ) + "_=" + ts : "" );
  
  xhr.open('POST', uploadUrl, true);  
  eventSource.onprogress = this.onUploadProgress(uploadInfo);
  xhr.setRequestHeader("Content-Type", "multipart/form-data");
  
  xhr.setRequestHeader('X-FILE-NAME', file.name);
  xhr.send(file);
  </code></pre>