Set the RenderView's layer's anchorPoint to 0,0

[smfr]

7c22044

Set the RenderView's layer's anchorPoint to 0,0
https://bugs.webkit.org/show_bug.cgi?id=249517
<rdar://problem/103528523>

Reviewed by Matt Woodrow.

Zooming code gets easier if we always give the RenderView's layer an anchor point of [0,0], instead of the default [0.5,0.5].
This layer is only ever transformed via pinch-zooming, so this does not affect web-exposed behavior. The transform can be set
on both the m_graphicsLayer and m_contentsContainmentLayer (see calls to setAppliesPageScale()).

To avoid the need for > 600 layout test rebaselines, add code to RenderLayerBacking::shouldDumpPropertyForLayer() to
control whether to dump the anchor point on the RenderView's layer; we'll only dump it if it has something other
than the default 0,0 value. Undoing this hack is tracked by webkit.org/b/249600.

Rebaseline some tests that show that zooming already left a 0,0 anchor point on the layers.

* LayoutTests/compositing/canvas/hidpi-canvas-backing-store-invalidation-2-expected.txt:
* LayoutTests/compositing/fixed-with-fixed-layout-expected.txt:
* LayoutTests/compositing/layer-creation/zoomed-clip-intersection-expected.txt:
* LayoutTests/fast/visual-viewport/tiled-drawing/zoomed-fixed-scrolled-down-expected.txt:
* LayoutTests/fast/visual-viewport/tiled-drawing/zoomed-fixed-scrolled-down-then-up-expected.txt:
* LayoutTests/fast/visual-viewport/tiled-drawing/zoomed-fixed-scrolling-layers-state-expected.txt:
* LayoutTests/platform/mac-wk2/compositing/tiling/tile-cache-zoomed-expected.txt:
* LayoutTests/platform/mac/compositing/tiling/tile-cache-zoomed-expected.txt:
* LayoutTests/tiled-drawing/scrolling/fixed-background/fixed-body-background-zoomed-expected.txt:
* LayoutTests/tiled-drawing/tile-size-slow-zoomed-expected.txt:
* LayoutTests/tiled-drawing/tiled-drawing-zoom-expected.txt:
* LayoutTests/tiled-drawing/tiled-drawing-zoom-scrolled-expected.txt:
* Source/WebCore/page/PageOverlayController.cpp:
(WebCore::PageOverlayController::shouldDumpPropertyForLayer const):
* Source/WebCore/page/PageOverlayController.h:
* Source/WebCore/platform/graphics/GraphicsLayer.cpp:
(WebCore::GraphicsLayer::dumpProperties const):
* Source/WebCore/rendering/RenderLayerBacking.cpp:
(WebCore::RenderLayerBacking::updateChildrenTransformAndAnchorPoint):
(WebCore::RenderLayerBacking::shouldDumpPropertyForLayer const):
* Source/WebCore/rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::shouldDumpPropertyForLayer const):
* Source/WebCore/rendering/RenderLayerCompositor.h:

Canonical link: https://commits.webkit.org/258284@main

6c2cc5e

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

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 50b2d14)

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

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 4846a0e)

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

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 7eaa2fb)

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

[webkit-early-warning-system]

EWS run on previous version of this PR (hash d8487f9)

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✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	❌ 🧪 gtk-wk2
	✅ 🧪 api-ios	❌ 🧪 mac-wk1	✅ 🧪 api-gtk
	✅ 🛠 tv	❌ 🧪 mac-wk2
	✅ 🛠 tv-sim	❌ 🧪 mac-AS-debug-wk2
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 5950e17)

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✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🛠 gtk	❌ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🧪 api-gtk
	✅ 🛠 tv	❌ 🧪 mac-wk2
	✅ 🛠 tv-sim	❌ 🧪 mac-AS-debug-wk2
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash f729cb0)

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

[webkit-early-warning-system]

EWS run on current version of this PR (hash 6c2cc5e)

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✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 gtk-wk2
	🧪 api-ios	✅ 🧪 mac-wk1	🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress
✅ 🛠 🧪 merge	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 258284@main (7c22044): https://commits.webkit.org/258284@main

Reviewed commits have been landed. Closing PR #7802 and removing active labels.