Created Issue: Asyncfileupload problem when hositng aspx page inside an iframe [27362]

Having problem with asyncfileupload control on page which is hosted inside an iframe.

Issue Description:
Create 3 aspx pages test1.aspx, test2.aspx, test3.aspx
On test1.aspx place an iframe control and set its src to 'test2.aspx'
On test2.aspx put an asyncfileupload control and a button. On the buttons postback event redirect it to test3.aspx (Response.redirec('test3.aspx')
Now run the application and upload the file through asyncfileupload control and then click on the button then what we have here is that though the page is redirected to test3.aspx, but its not inside the iframe but we see test3.aspx on the browser address bar.
On digging into the source code of asyncfileupload control i found on OnPreRender method a div is getting outputted

```
output.Write("<div id='" + ClientID + "'>");
output.Write(result);
output.Write("</div>");
```
which gets rendered before the doctype and ie shows the follwing error on developer tools console
HTML1113: Document mode restart from Quirks to IE9 Standards
Do note that the application is old hence its running in quircks mode by default.