[roll] Roll fuchsia [flatland] Optimize UberStruct memory allocation

UberStruct now uses `std::pmr` collections for all fields, plus a private
`std::pmr::monotonic_buffer_resource` that all collections allocate
from.

This *drastically* improves the time to destroy UberStructs in
Engine::SceneState::Clear():
   23.9us -> 12.9us

Engine::SceneState::Initialize() is also improved:
   78.5us -> 57.6us

(timings on x64 emu with 4 spinning squares)

This is a very clear indication that we should look for other
opportunities to optimize memory allocation for bounded-lifetime
collections

Engine::SceneState::Initialize() is also improved:
   78.5us -> 57.6us

(timings on x64 emu with 4 spinning squares)

This is a very clear indication that we should look for other
opportunities to optimize memory allocation for bounded-lifetime
collections.

Original-Bug: 487048356
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1569305
Original-Revision: 39fcf323fe8b007855aeb42d7505117b492af949
GitOrigin-RevId: 7c10a377c997f04cd80a68431bf085539ec5ef62
Change-Id: I438f9d006f05a9c6f0acf9e455a3bb16fc3f64ea
1 file changed
tree: ff02b80f63273bc09e8df18ac183fb9729adbcaf
  1. ctf/
  2. git-hooks/
  3. infra/
  4. third_party/
  5. cobalt
  6. flower
  7. jiri.lock
  8. MILESTONE
  9. minimal
  10. prebuilts
  11. README.md
  12. stem
  13. test_durations
README.md

Integration

This repository contains Fuchsia's Global Integration manifest files.

Making changes

All changes should be made to the internal version of this repository. Our infrastructure automatically updates this version when the internal one changes.

Currently all changes must be made by a Google employee. Non-Google employees wishing to make a change can ask for assistance in one of the communication channels documented at get involved.

Obtaining the source

First install Jiri.

Next run:

$ jiri init
$ jiri import minimal https://fuchsia.googlesource.com/integration
$ jiri update

Third party

Third party projects should have their own subdirectory in ./third_party.