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

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

首先定位现有的 FPS 显示，以及用于 CPU/GPU 计时的性能分析数据。明确第一目标是否是所提议的应用总时间百分比，并在考虑吞吐量之前，确定这些百分比应如何呈现和验证。当约定的 CPU/GPU 百分比与相关性能统计信息一同显示时，即表示完成。

由索引模型根据 Issue 内容生成。