commit 47d7cde88651dd47c624c1e1dd23efb78337639e
author François Doray <fdoray@chromium.org> Tue Nov 28 21:05:57 2023
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> Tue Nov 28 21:25:46 2023
tree 1395ef2d10484da71bb50f031145cc58b3790629
parent 4c48fa3be88df1b67a766938e4ec0c5dc38d918b

Revert "[a11y] Move some of serialization pipeline from RAI to cache."

This reverts commit b0fb6c7b87c7ba95326a9d7a2bb30e9d055ec315.

Reason for revert: crbug.com/1505157

Original change's description:
> [a11y] Move some of serialization pipeline from RAI to cache.
>
> This CL aims to start moving some of the code path starting from HandleAXEvent to ScheduleImmediateAXUpdate over to cache side. The old code is still left in RAI for legacy support.
>
> The aim is to eventually delete the code from RAI side, and then RAI would only be called from ProcessDeferredAccessibilityEvents to AXReadyCallback.
>
> ----------------------------
> Details (only explaining post-lifecyle mode):
> Before this CL, a11y events (kind of) go like this: AXObjectCacheImpl::PostPlatformNotification -> RenderAccessibilityImpl::HandleAXEvent which also calls AXObjectCacheImpl::AddPendingEvent --> RenderAccessibilityImpl::ScheduleImmediateAXUpdate -> AXObjectCacheImpl::ScheduleAXUpdate --> AXObjectCacheImpl::ProcessDeferredAccessibilityEvents -> RenderAccessibilityImpl::AXReadyCallback
>
> Note that -> doesn't mean direct calls. Some calls in the middle may have been skipped. The CL prevents these excessively unnecessary calls in between RAI (RenderAccessibilityImpl) and AXObjectCacheImpl. The calls now go like this (again kinda): AXObjectCacheImpl::PostPlatformNotification -> AXObjectCacheImpl::AddEventToSerializationQueue -> AXObjectCacheImpl::ScheduleImmediateSerialization -> AXObjectCacheImpl::ScheduleAXUpdate -> AXObjectCacheImpl::ProcessDeferredAccessibilityEvents -> RenderAccessibilityImpl::AXReadyCallback
>
> Notice how RAI is only called at the very end. Of course, to make this possible many of the side logic had to be moved too like the delaying code that used to be AXReadyCallback is now at AXObjectCacheImpl::ProcessDeferredAccessibilityEvents.
>
> This image describes the above: https://i.imgur.com/U3tODTX.png
> What the CL achieves is moving the code in the blue square over to the left-hand side, thus making the code stay in AXObjectCache longer and only move to RAI at RenderAccessibilityImpl::AXReadyCallback. The serialization delay is moved to ProcessDeferredAccessibilityEvents.
>
> ----------------------------
> Legacy scheduling mode (as opposed to post-lifecycle serialization) still uses the old code which goes back and forth between RAI and AXObjectCache. The reason they were not moved as well is that legacy mode will get removed eventually anyway. When legacy mode is removed, we can safely remove the old code from RAI.
>
> ----------------------------
> Also, with the cleaner code, it'll be feasible to change the scheduling logic further to limit some events like scrolling. Scrolling improvements discussed here https://docs.google.com/document/d/1fBK1BBrG8souqZpyv7q_3kxCYF1IYoXNPXmoVL7X8Gk/edit#heading=h.uo8ebdp7cxl
>
> ----------------------------
>
> Change-Id: I4662c29ee0185b8554b80b71db5ffb0aa6fc2319
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4994320
> Reviewed-by: Peter Beverloo <peter@chromium.org>
> Auto-Submit: Ahmed Elwasefi (Ahmad45123) <a.m.elwasefi@gmail.com>
> Reviewed-by: Aaron Leventhal <aleventhal@chromium.org>
> Reviewed-by: Jeremy Roman <jbroman@chromium.org>
> Commit-Queue: Ahmed Elwasefi (Ahmad45123) <a.m.elwasefi@gmail.com>
> Cr-Commit-Position: refs/heads/main@{#1227944}

Bug: 1505157
Change-Id: I5a233e3d015e639bb606940375767ed38bf2dd79
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5063728
Reviewed-by: danakj <danakj@chromium.org>
Commit-Queue: Francois Pierre Doray <fdoray@chromium.org>
Reviewed-by: Etienne Pierre-Doray <etiennep@chromium.org>
Auto-Submit: Francois Pierre Doray <fdoray@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Commit-Queue: Jeremy Roman <jbroman@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1230149}