Chrome Browser pinned tab tip.

If you use google chrome you might already know about how to use pinned tabs. 
Which gives extra space for other tabs. The pinned tab automatically goes to the left side on tab bar.
I use them for websites I use most. Examples are Google mail, calender, docs, facebook, twitter etc.
I don't know that it had following feature.
If you still wondering what it is here is simple screenshot of it if

If you drag a tab to the left side of in between of pinned tabs it snaps to the tab bar as pinned tab.

-- Anil