The Chrome keyboard does support Caps Lock, in a design inspired by Steve Jobs' old company. Here's a little history:
The original NeXTcube keyboard (circa 1989) also did not have a Caps Lock key. Instead, Caps Lock was engaged by pressing Command+Shift, which would light up matching green LEDs on both Shift keys. Caps Lock was disengaged by pressing the Shift key a second time. This freed up valuable keyboard real estate, eliminated the possibility of hitting Caps by accident, and allowed the Control key to be placed next to the "A" key, where it has always belonged. It's an excellent design.
Fast forward 20 years and Google is doing the same thing with the Chrome keyboard. Its Shift key also has a green LED to indicate Caps Lock. Presumbaly, Caps Lock is engaged in a similar way as the NeXT keyboard.
Unfortunately, they're putting a "Search" button there in its place, which is just stupid.