[skia-sync] Merge upstream Skia main (tip)

[mattleibow]

Automated bleeding-edge sync from the tip of upstream Skia (google/skia main).

Companion skia PR: mono/skia#273

Skia upstream main → mono/SkiaSharp main sync (tip mode)

This PR bumps SkiaSharp's externals/skia submodule to pick up upstream
google/skia main bug fixes (and the m151-in-progress refactor) without
advancing the SkiaSharp milestone or NuGet version.

It is the parent companion of the mono/skia PR for skia-sync/main.

Mode summary

Mode	main/tip sync (upstream_ref = main)
Base milestone (current)	m150
Target milestone	m150 (not a version bump)
Is release-line sync	false
Base branch	main
Head branch	skia-sync/main
Submodule before	280ec21adad7b21bdf8d8081a44c3191bb420fc3 (mono/skia skiasharp HEAD before the merge)
Submodule after	cebbc418885bf2d928b31fb3798da45cd31d4a7b (mono/skia skia-sync/main HEAD)
Submodule commits added	3 (merge from upstream + SK_MILESTONE pin + sk_font.cpp include fix)

What changed in the parent repo

File	Change
externals/skia	Submodule pointer: 280ec21ada → cebbc41888.
cgmanifest.json	upstream_merge_commit: 14d05ec761… → cebbc41888…. chrome_milestone stays 150.
native/android/build.cake	Added skia_use_partition_alloc=false to the GnNinja call.
native/ios/build.cake	Added skia_use_partition_alloc=false.
native/linux/build.cake	Added skia_use_partition_alloc=false to both the libSkiaSharp and libHarfBuzzSharp GnNinja calls (the Linux build is the only one that GnNinja-builds HarfBuzz).
native/macos/build.cake	Added skia_use_partition_alloc=false.
native/tizen/build.cake	Added skia_use_partition_alloc=false.
native/tvos/build.cake	Added skia_use_partition_alloc=false.
native/wasm/build.cake	Added skia_use_partition_alloc=false to both the libSkiaSharp and libHarfBuzzSharp sections (WASM also GnNinja-builds HarfBuzz).
native/windows/build.cake	Added skia_use_partition_alloc=false.

linuxnodeps/build.cake and linux-clang-cross/build.cake were not touched — they
delegate to linux/build.cake. Android/iOS/macOS/tvOS/Windows HarfBuzz are built
via NDK/Xcode/MSBuild rather than GnNinja, so no HarfBuzz-side flag is needed
there.

Why this gn arg is needed: Upstream main added a src/partition_alloc/BUILD.gn
target that pulls a partition_alloc.gni from ${skia_partition_alloc_dir} — a path
our DEPS does not vendor. The default skia_use_partition_alloc = is_clang would
make every clang build pull it in. Forcing the arg to false keeps every clang
platform building against our DEPS-pinned dependencies only. See skill gotcha #23.

Version impact

None. This is explicitly not a version bump:

• chrome_milestone stays 150.
• scripts/VERSIONS.txt: skia release m150, libSkiaSharp milestone 150, soname 150.0.0, increment 0 — all unchanged.
• NuGet package versions: unchanged.
• The submodule pins SK_MILESTONE to 150 (upstream main has advanced to 151) so the build's git-sync-deps task (which enforces SK_MILESTONE == VERSIONS.txt milestone) still passes.

Bindings (Phase 8)

• pwsh ./utils/generate.ps1 (via .agents/skills/update-skia/scripts/regenerate-bindings.ps1) ran cleanly.
• git status after regeneration: no changes to any *.generated.cs file.
• binding/HarfBuzzSharp/HarfBuzzApi.generated.cs auto-reverted by the script (skill gotcha Surface SKImage.Encode (SKImageEncoder type) #9 — HarfBuzz bindings are out-of-band).
• Conclusion: no new C API functions were exposed, so no C# wrapper work is required for this sync.

C# changes (Phase 9)

None beyond the items above. C# build:

dotnet build binding/SkiaSharp/SkiaSharp.csproj
Build succeeded. 0 Warning(s) 0 Error(s)

Build & test results (Phase 7 / Phase 10)

Native build (Linux x64):

dotnet cake --target=externals-linux --arch=x64

After adding skia_use_partition_alloc=false (see above), both libraries built cleanly:

• output/native/linux/x64/libSkiaSharp.so.150.0.0 (~11 MB)
• output/native/linux/x64/libHarfBuzzSharp.so.0.61421.0 (~2.8 MB)

Runtime deps verified (ldd): libfontconfig, libc++/libc++abi, libunwind, libm,
libc, ld-linux — same shape as before.

Tests (net10.0 | x64 | Linux):

dotnet test tests/SkiaSharp.Tests.Console/SkiaSharp.Tests.Console.csproj

Passed	5584
Failed	0
Skipped	172 (hardware/platform-specific: Metal, Tizen, DirectX, etc.)
Duration	2m 46s

Full test log is uploaded as the test-output.txt workflow artifact.

Items needing human attention

Cross-platform native build verification (HIGH PRIORITY). Only Linux x64 was
actually built in this workflow. The skia_use_partition_alloc=false change was added
to every clang build.cake to keep behavior consistent across platforms, but please
verify on macOS / iOS / tvOS / Android / Windows / WASM / Tizen that the gn arg is
accepted and that the build still produces the expected artifacts before merging.

SK_MILESTONE pin (in the submodule PR). Upstream main has bumped SK_MILESTONE to
151. To honor "tip mode = not a version bump" the submodule PR includes a one-line
fork patch pinning it back to 150. If this sync was intended to actually bump SkiaSharp
to m151, drop that pin in the submodule PR and update VERSIONS.txt, soname (150.0.0 →
151.0.0), NuGet versions, and chrome_milestone here in the parent PR.

Major upstream header refactor (FYI). Upstream deleted include/private/base/ and
src/base/ directories and moved the headers back to include/private/ and src/core/.
SkiaSharp's C API only referenced one such header (already fixed in the submodule PR).
If you maintain extra native code outside the submodule that includes private Skia
headers directly, you may need to update include paths there.

CG manifest update only — no other CG/security changes. chrome_milestone stayed at
150, so no Skia CVE re-querying is needed for this sync. The upstream_merge_commit
hash bump simply re-points the merge-base used by the security-audit skill.

Verification checklist

• Submodule pointer matches the head of mono/skia skia-sync/main (cebbc41888).
• cgmanifest.json upstream_merge_commit matches the submodule HEAD.
• No *.generated.cs files changed after regeneration.
• dotnet build binding/SkiaSharp/SkiaSharp.csproj succeeds, 0 warnings.
• dotnet test tests/SkiaSharp.Tests.Console passes 5584/5584 (172 skipped are hardware-only).
• scripts/VERSIONS.txt unchanged (milestone, soname, increment).
• macOS / iOS / tvOS / Android / Windows / WASM / Tizen builds verified after partition_alloc gn arg change. ← Requires human / CI confirmation.

Created by skia-upstream-sync.

[github-actions]

📦 Try the packages from this PR

Warning

Do not run these scripts without first reviewing the code in this PR.

Step 1 — Download the packages

bash / macOS / Linux:

curl -fsSL https://raw.githubusercontent.com/mono/SkiaSharp/main/scripts/get-skiasharp-pr.sh | bash -s -- 4289

PowerShell / Windows:

iex "& { $(irm https://raw.githubusercontent.com/mono/SkiaSharp/main/scripts/get-skiasharp-pr.ps1) } 4289"

Step 2 — Add the local NuGet source

dotnet nuget add source ~/.skiasharp/hives/pr-4289/packages --name skiasharp-pr-4289

More options

Option	Description
--successful-only / -SuccessfulOnly	Only use successful builds
--force / -Force	Overwrite previously downloaded packages
--list / -List	List available artifacts without downloading
--build-id ID / -BuildId ID	Download from a specific build

Or download manually from Azure Pipelines — look for the nuget artifact on the build for this PR.

Remove the source when you're done:

dotnet nuget remove source skiasharp-pr-4289

[github-actions]

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