Consider two modes for Timeline FPS chart

[kenzieschmoll]

Per discussion here: https://docs.google.com/a/google.com/document/d/1hxl-ZOS6prsSSqvdYemnUHteme8uY7hUg04Nj4NRq5I/edit?disco=AAAACu7djgA, it might be useful to have two modes for the bar chart:

• A) one that is latency aware (current implementation where total sum of UI work and GPU work should fall under 16ms - bars stacked)
• B) one that is concerned only with throughput (both UI work and GPU work get a 16ms threshold - bars side by side)

[kenzieschmoll]

Perhaps we could have a checkbox that says "Latency aware" or "Track latency" that would switch to the mode we currently have in the Timeline.

Based on feedback from @liyuqian and others, I think we want option B) to be the default mode for the Timeline.

@terrylucas, how much time would it take to tweak the timeline plotly chart to support option B in addition to our current implementation (option A).