Clarification on Timing area

[joe g]

I am a bit confused as to the data that is displayed in the Timing area of Dev tools under the Performance tab. As I understand it, this area displays any W3C User timing marks, which seems to work well. However, in running a performance test for the test AngularJS page - https://angular.io/guide/quickstart, I discovered the following references listed there: 

Zone 

• Zone Aware Promise 
  
• Zone: to string 
  
• Zone: timers 
  
• Zone: Blocking 
  
• Zone: Event Target 
  
• Zone: on property 
  
• Zone: custom elements
  
•  Zone: Canvas 
  
• Zone: XHR 
  
• Zone: Location
  
• Zone: Promise Rejection Event
  

In looking over the code I don't see the typical coding references to add such a mark - e.g. window.performance && performance.mark && performance.mark("ATFAreaBegin") See https://www.w3.org/TR/user-timing/? 

So I am curious as to:

1. Why are these timings  listed in this section? Is the Timing section showing other types of timing events beyond the W3C user timing? I had assumed that only W3C timing marks would appear in this section These timings appear to be standard out of box in AngularJS since I didnt add anything to the code..
2. Is anyone aware of documentation on the purpose of these and how they relate to web performance.