Advice for troubleshooting hard freezes associated with Safari? (Mid 2012 Retina Macbook Pro, 10.10.2)

I have a Macbook Pro 10,1 (Mid 2012) running 10.10.2. Over the last few months, I have had issues with the system suddenly hanging - mouse won't move, keyboard does nothing, and the clock is stopped. I have to hold down the power button and restart the computer when this happens.

I have been experiencing these freezes ranging from daily to weekly. There is no consistent action that reproduces the freeze on demand. At some point in the last few months, though, I did switch to Safari from Chrome as my primary browser because the battery life seems so much better when using Safari. I've been doing a project over the last week that is dependent on Chrome, and as such haven't been using Safari, and have had no freezes. In retrospect, I think the freezes began happening when I started using Safari regularly.

I'd prefer to not have to choose between using Safari and having a stable system. Is anyone aware of issues like the one I'm experiencing? Any suggestions for further troubleshooting?