I figured out the answer to my problem. Here's the piece of code:
<div style="overflow:hidden;">
<div>
<input type="text"></input>
</div>
</div>
It was the "overflow:hidden" style that was causing the problem. After removing it, the issue got fixed. Here's a jsfiddle for the problem. Just zoom out a little in chrome, and the lower border of the input text disappears.