tree 4bdc622a74e7cb10c98258301d77f24cab1c7797
parent e43a2a568976b495cbbb8d4ec8f89cc1563c5518
author Eric Seckler <eseckler@google.com> 1583258665 +0000
committer Eric Seckler <eseckler@google.com> 1583258665 +0000

protos: Add support for counters in TrackEvent

Adds a generic way to describe counter tracks and supply counter values
in TrackEvents.

We support two types of counters: built-in (e.g. thread time,
instruction count) and custom user-specified. Counter values can be
provided in separate TrackEvents of TYPE_COUNTER, or attached to other
slice-type TrackEvents (i.e. at beginning/end of a slice).
Delta-encoding of counter values is also supported.

This will enable us to support TRACE_COUNTER macros in the client
library as well as experiment with more per-event counters in Chrome
(see crrev.com/c/1940179 for related discussion about the latter).

Design doc:
https://docs.google.com/document/d/1yL-OIm6k7IyjZ9xWkwcyA1F_4i6_uJj63qmEVTWCg_U/edit?usp=sharing

Bug: 123864183
Change-Id: Icec416b8efbdd46b4bef04491c7a9bcfa74142f9