Default [Q] Dynamically Changing Display Refresh Rate

Assuming I have access to the source code for all of the OS as well as the display drivers, would it be possible to dynamically adjust the refresh rate of the display on a modern mobile device (e.g. Nexus 4 or 5)?

I want to be able to do this in order to reduce display power consumption. I know that CPU and GPU can be manipulated using DVFS. Is it reasonable to expect that something similar exists for the display driver, or am I just barking up the wrong tree here?