tree fa67dd4b24f14dda912a52d2e4a4279c1b8699ef
parent 91feed662c315a8fee1f716af09005fd29879bcb
author Violetta Fedotova <violettfaid@google.com> 1662140902 +0000
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> 1662140902 +0000

Split `GenerationToRendererCompositor` breakdown to
`GenerationToBrowserMain` and `BrowserMainToRendererCompositor`.


This CL solves problem that there is no way to say what is causing the long
delay -- Browser or Renderer. New breakdowns make it clearer where time was
spent:
 - [KGenerated, kArrivedInBrowserMain] = "GenerationToBrowserMain". This is
 the time before input arrived to the Browser process.
 - [kArrivedInBrowserMain, kArrivedInRendererCompositor] =
 "BrowserMainToRendererCompositor". This is time before input arrived to
 the Render process. Including queuing in Browser.
Currently these breakdowns are added for ScrollBegin and ScrollUpdate for
now, but in next CL it will be added for others EventLatencies. Also we are
going to add a new breakdown for queuing time in browser main.


Result:
 - link: https://ui.perfetto.dev/#!/?s=e2e8ca759182689ab191d1ec67a3e59f44d7e698d754c2e60bad2362fc573b7
 - screenshot: https://screenshot.googleplex.com/8ezhHtVCBmvnzZi

Bug: b/224960731
Change-Id: I703553f886a6c59190b40f34f2972cff9836dbc5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3803196
Reviewed-by: ccameron chromium <ccameron@chromium.org>
Reviewed-by: Steve Kobes <skobes@chromium.org>
Auto-Submit: Violetta Fedotova <violettfaid@google.com>
Commit-Queue: Violetta Fedotova <violettfaid@google.com>
Reviewed-by: Mohsen Izadi <mohsen@chromium.org>
Reviewed-by: Stephen Nusko <nuskos@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1042662}