[WebXR] Revert WebXRSession changes from 312788@main

[djg]

3c73508

[WebXR] Revert WebXRSession changes from 312788@main
https://bugs.webkit.org/show_bug.cgi?id=314623
rdar://176829186

Reviewed by Cameron McCormack.

312788@main moved applyPendingRenderState() from before the rendering block
to after it in WebXRSession::onFrame(), and moved inputSources->update()
to run unconditionally before the render block. These changes were made to
fix an OpenXR-specific crash involving swapchain acquire/release mismatches
when activeLayerHandles changed mid-frame.

The OpenXR author has confirmed these WebXRSession changes are no longer
required for OpenXR -- the OpenXR-side changes in that commit (snapshotting
active layers at beginFrame and filtering at endFrame) are sufficient to
prevent the crash without modifying the shared WebXRSession frame loop.

Reverting restores the original frame loop ordering:
- applyPendingRenderState() before frameShouldBeRendered() (step 7 before 6)
- inputSources->update() at step 6.4 inside the render block

This fixes first-frame rendering on visionOS where the deferred
applyPendingRenderState meant frameShouldBeRendered() would see a null
baseLayer and skip the entire render block.

* Source/WebCore/Modules/webxr/WebXRSession.cpp:
(WebCore::WebXRSession::applyPendingRenderState):
(WebCore::WebXRSession::onFrame):
(WebCore::WebXRSession::updateRequestDataFromActiveRenderState): Deleted.
* Source/WebCore/Modules/webxr/WebXRSession.h:

Canonical link: https://commits.webkit.org/313131@main

726ac8a

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	⏳ 🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	🧪 win-tests	⏳ 🛠 mac-apple
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	🧪 api-mac	✅ 🧪 api-wpe		⏳ 🛠 vision-apple
	🧪 ios-wk2-wpt	🧪 api-mac-debug	✅ 🛠 gtk3-libwebrtc
⏳ 🛠 🧪 jsc	🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 ios-safer-cpp	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision	🧪 mac-AS-debug-wk2	🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 6f3921b)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	⏳ 🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	❌ 🧪 win-tests	⏳ 🛠 mac-apple
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe		⏳ 🛠 vision-apple
	✅ 🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 gtk3-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 ios-safer-cpp	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[svillar]

Are you sure the commit is the one mentioned in the ChangeLog? Shouldn't be b0baaea instead?

[svillar]

Actually I think we might not even need this. We can keep everything together now because we have applied countermeasures at OpenXR side which will allow us to produce sensible rendering even if the processes disagree about the active layers.

Contrary to what I mentioned in my previous commits applying the render state above would still be conformant to the spec because it happens before calling the frame callbacks. This means that calling updateRenderState() during rAF won't change the current frame because the render state has been applied before.

That's why I think it'd be better to avoid splitting these calls and keep the code together in apply render state as it was before my change. OpenXR should be fine.

[djg]

So you're fine with me reverting the changes to WebXRSession made in b0baaea?

[webkit-early-warning-system]

EWS run on current version of this PR (hash 726ac8a)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win	⏳ 🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	🧪 win-tests	⏳ 🛠 mac-apple
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	🧪 api-mac	✅ 🧪 api-wpe		⏳ 🛠 vision-apple
	🧪 ios-wk2-wpt	🧪 api-mac-debug	✅ 🛠 gtk3-libwebrtc
⏳ 🛠 🧪 jsc	🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	✅ 🛠 ios-safer-cpp	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision	🧪 mac-AS-debug-wk2	🧪 api-gtk
✅ 🛠 🧪 merge	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 playstation
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2
	✅ 🛠 tv	✅ 🛠 mac-safer-cpp
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 313131@main (3c73508): https://commits.webkit.org/313131@main

Reviewed commits have been landed. Closing PR #64744 and removing active labels.