JS Fiddle Demo
HTML
textarea.blur()
textarea.focus()
Does the job.
Example: https://jsfiddle.net/syy25x69/
To select a text in IE see: Set textarea selection in Internet Explorer
Update
In order for this to work, I noticed that the selection must be collapsed. You can restore the selection later if you need to.
// collapse selection here
textarea.blur()
textarea.focus() // this scrolls the textarea
// expand selection here
Another example: https://jsfiddle.net/rk8cL174/