Expose an application's total execution time as a percentage of CPU/GPU. #1300

Could imagine stats:

1. Total app time:
   30% of app's time is GPU
   70% of app's time is CPU
2. CPU/GPU throughput:
   80% of total CPU throughput is consumed by this app
   20% of total GPU throughput is consumed by this app

The first should be fairly easy. Kenzie suggested that current FPS should be displayed with %GPU as well (first one "Total app time").

The second one, seems hard unless we have some way of knowing for each GPU/CPU type what is the (max cycles / time period) or if there is a test we could run to find what pegging the CPU/GPU means to known how much of CPU/GPU is being used by this app.

@liyuqian @kenzieschmoll