Where did these key designations came from?  
Chrome for the Mac uses cmd+<+/-/0>, Chrome for Windows Uses shift+alt+<+/-/0>
Photoshop for Mac uses cmd+<+/-/0> Photoshop for Windows uses ctrl+<+/-/0>
Windows also uses a Control+Scroll Wheel Zoom which is standard and accelerated on certain keyboards.

I'd prefer the Photoshop key combos since I spend a lot of time there and this seems natural but can we also implement the scroll wheel on Windows to zoom?