Remove longstanding iOS-specific image painting antialiasing quirk

[hortont424]

ef3ae0b1e9717221ac7c094161fa75cae8fd99b4

Remove longstanding iOS-specific image painting antialiasing quirk
https://bugs.webkit.org/show_bug.cgi?id=246551
rdar://100183888

Reviewed by NOBODY (OOPS!).

* Source/WebCore/platform/graphics/cg/GraphicsContextCG.cpp:
(WebCore::GraphicsContextCG::drawNativeImage):
In the interests of platform unity, remove this longstanding iOS image painting
quirk; it can cause pixel cracks in some cases, and there is no reason for iOS
image painting to differ from macOS at this point (it was originally introduced
for performance on very early hardware).

https://github.com/WebKit/WebKit/commit/ef3ae0b1e9717221ac7c094161fa75cae8fd99b4

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

[webkit-early-warning-system]

EWS run on current version of this PR (hash https://github.com/WebKit/WebKit/commit/ef3ae0b1e9717221ac7c094161fa75cae8fd99b4)

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

[aproskuryakov]

Do you expect zero impact on benchmarks, no chance of 1% regression somewhere?

[hortont424]

Do you expect zero impact on benchmarks, no chance of 1% regression somewhere?

I am going to kick off some benchmarks; first I wanted to see what the tests say.

[hortont424]

This is a 3-5% motionmark regression, so I will find another way :(

[aproskuryakov]

Let's extend this quirk to macOS? :)

[hortont424]

Let's extend this quirk to macOS? :)

Definitely not going to regress correctness on macOS for an optimization that should never have landed :) I am going to fix my pixel cracks a different way, and will just leave this be :(