ImageBuffer has unused virtual function cloneForDifferentThread()

[kkinnunen-apple]

d2ed32a

ImageBuffer has unused virtual function cloneForDifferentThread()
https://bugs.webkit.org/show_bug.cgi?id=261736
rdar://115721857

Reviewed by Said Abou-Hallawa.

The function was used as the RemoteImageBufferProxy implementation of
the real payload function
ImageBuffer::sinkIntoBufferForDifferentThread().

Remove the function, it's not needed. Use the implementation to
implement RemoteImageBufferProxy::sinkIntoBufferForDifferentThread()
override.

* Source/WebCore/platform/graphics/ImageBuffer.cpp:
(WebCore::ImageBuffer::cloneForDifferentThread): Deleted.
* Source/WebCore/platform/graphics/ImageBuffer.h:
* Source/WebKit/WebProcess/GPU/graphics/RemoteImageBufferProxy.cpp:
(WebKit::RemoteImageBufferProxy::sinkIntoBufferForDifferentThread):
(WebKit::RemoteImageBufferProxy::cloneForDifferentThread): Deleted.
* Source/WebKit/WebProcess/GPU/graphics/RemoteImageBufferProxy.h:

Canonical link: https://commits.webkit.org/268186@main

967f54d

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	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash 967f54d)

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	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 268186@main (d2ed32a): https://commits.webkit.org/268186@main

Reviewed commits have been landed. Closing PR #17912 and removing active labels.