The Focus Area tool is not part of Photoshop CC. It is in the new version Photoshop CC (2014). You will have to download and install this new version...
And just as a reminder: Once you install it, you have to run the new one from the new location, not the old one. Some folks are starting the old version still with icons on their desktop, etc.
Ok, installed cc2014, made sure I ran the updates.
Opened 2014 and attempted to use the Focus Mask, and it caused cc2014 to crash.
So far not impressed with CS6-CC, nor CC2014. I do have the annual paid subscription, but I doubt very seriously that I will continue with the product after my 1yr subscription,
I have a perpetual license for CS5 and CS6, guess I will stay with the basic versions, even though they are not capable of updating anymore. But at least they work without issues.