Auto Play Video in Chrome

I have a video URL that is embedded in HTML iframe tag. It, iframe, auto plays the video in IE and Firefox. But it does not auto play in Chrome.

If I paste the URL of the video directly in the address bar, it does auto play in all browsers.

I caot seem to figure out what is different in Chrome.

Update

During testing, I found out that if I disable flash using chrome://plugins/, video does play automatically when page loads?