REGRESSION(267824@main): Changing HTMLCanvasElement width, height causes intermediate buffer allocations

[kkinnunen-apple]

26aaa25

REGRESSION(267824@main): Changing HTMLCanvasElement width, height causes intermediate buffer allocations
https://bugs.webkit.org/show_bug.cgi?id=268745
rdar://122309325

Reviewed by Simon Fraser.

Resizing is intended to leave the buffer unallocated, so that
sequential width, height assignments will not allocate multiple times.

This intention was nullified by CanvasRenderingContext2DBase::reset().
Calling resetTransform redundantly would recreate the buffer
immediately from width, height attribute setters.

The transform reset is redundant, the context transform is reset when
the context state saver is restored and re-saved.

Clearing the canvas doesn't need to use public
CanvasRenderingContext2DBase::clearCanvas() that will mutate the context
state. The state is in known state with initial transform, and thus it
doesn't need transform mutation.

* Source/WebCore/html/canvas/CanvasRenderingContext2DBase.cpp:
(WebCore::CanvasRenderingContext2DBase::reset):

Canonical link: https://commits.webkit.org/274135@main

c4bdacb

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
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✅ 🧪 services	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 jsc-armv7
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 8e2a87e)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	🧪 wpe-wk2
✅ 🧪 webkitperl	🧪 ios-wk2	⏳ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	🧪 mac-wk1	✅ 🛠 gtk
	✅ 🧪 api-ios	⏳ 🧪 mac-wk2	🧪 gtk-wk2
	⏳ 🛠 tv	🧪 mac-AS-debug-wk2	🧪 api-gtk
	⏳ 🛠 tv-sim
	⏳ 🛠 watch
	⏳ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash f531600)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	❌ 🧪 wpe-wk2
✅ 🧪 webkitperl	❌ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	🧪 mac-wk1	✅ 🛠 gtk
	✅ 🧪 api-ios	⏳ 🧪 mac-wk2	❌ 🧪 gtk-wk2
	✅ 🛠 tv	🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash c4bdacb)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
✅ 🧪 webkitpy	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 gtk
✅ 🛠 🧪 jsc	✅ 🧪 api-ios	🧪 mac-wk2	✅ 🧪 gtk-wk2
✅ 🛠 🧪 jsc-arm64	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
✅ 🧪 services	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress	✅ 🛠 jsc-armv7
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 274135@main (26aaa25): https://commits.webkit.org/274135@main

Reviewed commits have been landed. Closing PR #23861 and removing active labels.