Chrome 52 is all about Google’s Material Design, which means the UI is a little more flat and a bunch of the icons have changed. This means tab shapes are different, icons are totally changed, and the ominbox is redesigned to match the mobile apps. Good news though, if you’re not a fan of the new design, you can disable it:
In the URL bar, type in chrome://flags and press Enter.
Search for “Material Design in the browser’s top chrome” and set it to either “Non Material” to revert back to the previous interface, or “Material Hybrid” to enable a hybrid mode. We can’t tell what exactly is different from the hybrid and default modes though.
With that, you can continue on your merry way, ignoring Google’s newest design.
Source: https://lifehacker.com/how-to-ditch-chromes-new-material-design-and-get-the-ol-1784822156