Hanging a heavy edgeless mirror so that it tilts down

I have a mirror similar to this:

I'd like to hang it like this:

…where the angle can be easily adjusted whenever I'd like.

I'd like to figure out how to simply, cheaply, and securely (living in CA – earthquakes may strike again) achieve this. I was considering using french cleats like this on the bottom edge of the mirror:

… and then some D-rings up top to control the angle. But I don't know if the "lean" of the cleat will damage the wall at the bottom if I do this.

Another alternative is to just build a thin shelf with a small lip, but I'm trying to go as minimal / unobtrusive as possible here. I'd prefer not to see any hardware.