[skia-sync] Merge upstream chrome/m148 bug fixes

[mattleibow]

Automated upstream bug-fix sync for m148. Targeting release branch release/4.148.x (mono/skia release/4.148.x).

Companion skia PR: mono/skia#268

Summary

Release-line bug-fix sync onto release/4.148.x. Bumps the externals/skia submodule pointer to pick up 2 new upstream chrome/m148 bug fixes and updates the matching cgmanifest.json SHAs.

This is not a milestone bump — CURRENT == TARGET == 148. No version files change: scripts/VERSIONS.txt, scripts/azure-templates-variables.yml, SkMilestone.h, SK_C_INCREMENT are all left exactly as they are on release/4.148.x. The only file changes in this PR are:

• externals/skia submodule pointer: 1a155bae3a → 6d45d9aed1
• cgmanifest.json mono/skia commitHash: 1a155bae3ac86db6d3efbd996f00e774b6a7b722 → 6d45d9aed12bacb599261ccebcf4a9764b0467ea
• cgmanifest.json Skia-core upstream_merge_commit: 54851b68b7a1d49bc4b4361f12786a7d7ad91fff → 46f2e16555cac1211f4087cf24728fd741ac6495

chrome_milestone stays at 148.

Companion mono/skia PR

mono/skia PR on branch skia-sync/release-4.148.x targeting release/4.148.x. That PR carries the actual upstream merge commit 6d45d9aed1. Per the skill's merge sequence, the mono/skia PR must be merged first; then the parent repo's submodule pointer must be re-pointed at the squashed release/4.148.x SHA before merging this PR.

Upstream commits pulled in (via submodule bump)

SHA	Subject	Files
46f2e16555	[m148] Resolved a Data Race on fStream in SkTypeface_Mac	src/ports/SkTypeface_mac_ct.{cpp,h}
3a90f6662a	[graphite] Use stable collection for static bindings	src/gpu/graphite/dawn/DawnGraphicsPipeline.cpp

Both are upstream cherry-picks already on chrome/m148. The macOS typeface fix is the user-visible one (eliminates a gTFCache/fStream data race in SkTypeface_Mac); the Graphite change is benign for SkiaSharp because we ship Ganesh, not Graphite/Dawn.

Breaking change analysis

None. Because this is a release-line bug-fix sync (current == target == 148):

• No public C++ API was added, removed, or renamed by these two commits.
• No C API (externals/skia/src/c/**, include/c/**) files changed.
• The binding generator re-ran and reports No changes to bindings (C API signatures unchanged) and No new functions found. binding/SkiaSharp/SkiaApi.generated.cs and the other *Api.generated.cs files are byte-identical to origin/release/4.148.x.
• No managed C# wrapper changes required.
• No [Obsolete] markers to add — no deprecations.
• ABI / soname stay at libSkiaSharp.so.148.0.0.

Version / binding updates

File	Change
scripts/VERSIONS.txt	unchanged (milestone 148, increment 0, soname 148.0.0)
scripts/azure-templates-variables.yml	unchanged
externals/skia/include/core/SkMilestone.h	unchanged (SK_MILESTONE 148)
externals/skia/include/c/sk_types.h (SK_C_INCREMENT)	unchanged (0)
binding/SkiaSharp/SkiaApi.generated.cs	unchanged (regenerated, no diff vs base)
binding/SkiaSharp.Skottie/SkottieApi.generated.cs	unchanged
binding/SkiaSharp.SceneGraph/SceneGraphApi.generated.cs	unchanged
binding/SkiaSharp.Resources/ResourcesApi.generated.cs	unchanged
binding/HarfBuzzSharp/HarfBuzzApi.generated.cs	unchanged (HarfBuzz regen is reverted by the regenerate-bindings script per policy)
cgmanifest.json	mono/skia commitHash + Skia-core upstream_merge_commit bumped
externals/skia (submodule pointer)	bumped to 6d45d9aed1

C# changes

None required. No managed code was modified, no test code was modified.

Build / test results (Linux x64)

The agent used dotnet cake --target=externals-linux --arch=x64 (NOT externals-download, per the skill's hard rule for milestone-touching work). Other platforms (macOS, Windows, iOS, Android, WASM) will rebuild on the release-line CI pipelines once both PRs land.

Stage	Result
dotnet tool restore	✅ all tools restored
git submodule status	✅ aligned to base before merge
Upstream merge (in submodule)	✅ clean, no conflicts, git diff --check empty
cgmanifest.json edit	✅
dotnet cake --target=externals-linux --arch=x64	✅ produced output/native/linux/x64/libSkiaSharp.so.148.0.0 (11.3 MB) and libHarfBuzzSharp.so.0.61420.0 (3.0 MB) — total native build ≈ 16 min
regenerate-bindings.ps1	✅ No changes to bindings, No new functions found, HarfBuzz revert applied
dotnet build binding/SkiaSharp/SkiaSharp.csproj	✅ 0 errors, 0 warnings, all TFMs (net462/net48/netstandard2.0/2.1/net6.0/net9.0/net9.0-android35.0/net10.0/net10.0-android36.0)
Smoke tests (Category=Smoke)	✅ 32 passed, 0 failed, 0 skipped (131 ms)
Full test suite	✅ 5544 passed, 0 failed, 172 skipped (HW-dependent), 5716 total — 2 m 32 s

The full suite was first attempted with xUnit's default parallel test execution and crashed in test discovery with PAL_SEHException: Out of memory on the 16 GB CI runner. Re-running with xUnit.MaxParallelThreads=1 xUnit.ParallelizeTestCollections=false (serial execution) completed cleanly with 0 failures. This is an environmental constraint of this CI runner, not a regression introduced by the merge.

Items needing human attention

• Cross-platform reviewers, please double-check the macOS native build picks up the new SkTypeface_mac_ct.cpp mutex correctly on the release/4.148.x macOS / iOS / Mac Catalyst pipelines. The change is upstream-mainline and small (8 line diff), so risk is low, but the agent only built Linux x64 here.
• Merge sequence (from the skill, repeated for the human merger):
  1. Merge the mono/skia skia-sync/release-4.148.x → release/4.148.x PR first (squash).
  2. In this repo, git -C externals/skia fetch origin && git -C externals/skia checkout <new-squashed-sha-on-release/4.148.x>, commit, push to this PR branch.
  3. Re-run CI; merge this PR last.
     Skipping step 2 would orphan the submodule onto the unsquashed branch commit.
• No native-build dependency issues, no gn arg changes, no compiler/linker flag changes were required for this sync.

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 -- 4262

PowerShell / Windows:

iex "& { $(irm https://raw.githubusercontent.com/mono/SkiaSharp/main/scripts/get-skiasharp-pr.ps1) } 4262"

Step 2 — Add the local NuGet source

dotnet nuget add source ~/.skiasharp/hives/pr-4262/packages --name skiasharp-pr-4262

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-4262