[migration] Make upstream Skia synchronization portable

Resolve the current SkiaSharp repository at runtime and the paired Skia repository from .gitmodules across detection, metadata, delivery, and direct submodule synchronization. Preserve guarded dual-repository delivery while validating mono, dotnet, and release-line behavior.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 8250c1ca-20e4-461e-bad3-9e2864ad57ea

Author: v

.agents/skills/ci-status/scripts/tests/test_workflow_registry.py

@@ -205,5 +205,21 @@ def test_documented_schedules_match_the_workflow(self):
                          f"SKILL.md rows name untracked workflows: {unresolved}")
 
 
+class SubmoduleSyncIdentityTests(unittest.TestCase):
+    def test_identity_tooling_is_staged_before_target_checkout(self):
+        workflow = load_workflow("auto-skia-submodule-sync.yml")
+        steps = workflow["jobs"]["sync"]["steps"]
+        names = [step.get("name") for step in steps]
+        stage_index = names.index("Stage identity tooling")
+        checkout_index = names.index("Checkout SkiaSharp")
+        validate_index = names.index("Validate branches")
+        self.assertLess(stage_index, checkout_index)
+        self.assertLess(checkout_index, validate_index)
+        self.assertIn(
+            '$IDENTITY_SCRIPT" --root "$GITHUB_WORKSPACE"',
+            steps[validate_index]["run"],
+        )
+
+
 if __name__ == "__main__":
     unittest.main()

.agents/skills/update-skia/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: update-skia
 description: >
-  Update the Skia graphics library to a new Chrome milestone in SkiaSharp's mono/skia fork.
+  Update the Skia graphics library to a new Chrome milestone in SkiaSharp's paired Skia fork.
   Handles upstream merge, fork-patch preservation, dependency compatibility, C API adaptation,
   binding regeneration, full backend testing, and coordinated dual-repo PRs.
 
@@ -17,8 +17,9 @@ The workflow only supplies resolved inputs, a prepared host, and automated PR de
 
 `Skia C++ -> SkiaSharp C API -> generated P/Invoke -> managed wrappers`
 
-Run from the mono/SkiaSharp repository root. Each phase lives in a separate reference so only
-the current work enters context.
+Run from the current SkiaSharp repository root resolved by
+`python3 scripts/infra/repository_identity.py get repository`. Each phase lives in a separate
+reference so only the current work enters context.
 
 ## Start state
 
@@ -33,8 +34,8 @@ names.
 | `{UPSTREAM_REF}` | `SKIA_SYNC_UPSTREAM_REF` | `chrome/m{TARGET}` or `main` |
 | `{BASE_BRANCH}` | `SKIA_SYNC_BASE_BRANCH` | Parent PR base |
 | `{PARENT_BASE_SHA}` | `SKIA_SYNC_PARENT_BASE_SHA` | Exact parent base commit used for metadata comparison |
-| `{SKIA_BASE_BRANCH}` | `SKIA_SYNC_SKIA_BASE_BRANCH` | mono/skia PR base |
-| `{SKIA_BASE_SHA}` | `SKIA_SYNC_SKIA_BASE_SHA` | Exact mono/skia commit recorded by the parent base |
+| `{SKIA_BASE_BRANCH}` | `SKIA_SYNC_SKIA_BASE_BRANCH` | Paired Skia PR base |
+| `{SKIA_BASE_SHA}` | `SKIA_SYNC_SKIA_BASE_SHA` | Exact paired Skia commit recorded by the parent base |
 | `{HEAD_BRANCH}` | `SKIA_SYNC_HEAD_BRANCH` | Feature branch used in both repositories |
 | `{IS_RELEASE}` | `SKIA_SYNC_IS_RELEASE` | Whether the selected base is a release line |
 | `{BASE_UPSTREAM_SHA}` | `SKIA_SYNC_BASE_UPSTREAM_SHA` | Exact upstream commit recorded by the parent base |
@@ -57,19 +58,19 @@ mkdir -p "$ARTIFACT_DIR"
 An update is complete only when:
 
 - The authoritative old-upstream-to-target range was analyzed before merging.
-- The mono/skia result is a genuine two-parent merge with every fork patch and dependency
+- The paired Skia result is a genuine two-parent merge with every fork patch and dependency
   decision accounted for.
 - The updated native source builds; downloaded old native artifacts were never substituted.
 - Bindings were regenerated and every required managed wrapper was reviewed.
 - The final **unfiltered** `tests/SkiaSharp.Tests.Console.slnx` run passes every host, including
   every GPU backend required by `GpuPolicy` on the validation host.
-- The parent points to the exact tested mono/skia commit.
+- The parent points to the exact tested paired Skia commit.
 - Both PR descriptions identify untested platforms and are ready for human review.
 
 ## Working rules
 
 - Create feature branches in both repositories before changes; never commit to protected branches.
-- Use a genuine two-parent merge in mono/skia; never use a tree-override merge.
+- Use a genuine two-parent merge in the paired Skia repository; never use a tree-override merge.
 - Preserve every fork patch unless upstream contains an equivalent or improved form.
 - Mark a removed patch `upstreamed` only after enumerating every independent behavior in its old
   delta and locating each one in the target; one upstreamed hunk does not cover another lost hunk.

.agents/skills/update-skia/references/known-gotchas.md

@@ -46,7 +46,7 @@ Also watch for renamed/removed GN flags between milestones — obsolete flags ca
 
 ### 7. `.gitmodules` Branch Name
 
-When the mono/skia target branch name changes, `.gitmodules` must be updated to track the new branch. Easy to forget; causes silent submodule tracking failures.
+When the paired Skia target branch name changes, `.gitmodules` must be updated to track the new branch. Easy to forget; causes silent submodule tracking failures.
 
 ### 19. Fork-Only GN `declare_args` Cleanup
 
@@ -186,7 +186,7 @@ git log --oneline "$MB..{SKIA_BASE_BRANCH}" > "$ARTIFACT_DIR/fork-patches-before
 ```
 
 For **every conflicted file**, find which fork patch(es) from that list touch it and classify each as
-*upstreamed* or *re-applied* (above). Every such patch must appear in the mono/skia PR's "Conflicts
+*upstreamed* or *re-applied* (above). Every such patch must appear in the paired Skia PR's "Conflicts
 resolved" table with its disposition. A fork patch on a conflicted file that is **neither** upstreamed
 nor re-applied is a lost patch — STOP and fix it before committing the merge. (Fork patches whose files
 did not conflict merge cleanly and need no listing.)

.agents/skills/update-skia/references/phases/01-03-research.md

@@ -10,15 +10,15 @@ For a developer-run update:
 
 1. Confirm the parent and `externals/skia` worktrees are clean.
 2. Initialize submodules and verify `git`, `gh`, Python 3, and the .NET SDK are available.
-3. Fetch the parent base candidates and mono/skia base candidates.
-4. Ensure mono/skia has an `upstream` remote for `https://github.com/google/skia.git`.
+3. Fetch the parent base candidates and paired Skia base candidates.
+4. Ensure the paired Skia repository has an `upstream` remote for `https://github.com/google/skia.git`.
 5. Check both repositories for an existing PR or branch for the requested target. Continue an
    existing update only when its bases and upstream ref match; never overwrite unrelated work.
 
 Resolve these values, including `IS_RELEASE`, and export the corresponding `SKIA_SYNC_*`
 variables from `SKILL.md`:
 
-| Request | Parent base | mono/skia base | Upstream ref | Head |
+| Request | Parent base | Paired Skia base | Upstream ref | Head |
 |---|---|---|---|---|
 | Newest milestone | `main` | `skiasharp` | `chrome/m{TARGET}` | `skia-sync/m{TARGET}` |
 | Older supported milestone | existing matching release branch in both repos | same release branch | `chrome/m{TARGET}` | `skia-sync/release-…` |
@@ -36,8 +36,8 @@ For automation, consume the supplied values instead and verify the referenced br
 Fetch:
 
 - `origin/{BASE_BRANCH}` in the parent.
-- `origin/{SKIA_BASE_BRANCH}` in mono/skia.
-- `upstream/{UPSTREAM_REF}` in mono/skia.
+- `origin/{SKIA_BASE_BRANCH}` in the paired Skia repository.
+- `upstream/{UPSTREAM_REF}` in the paired Skia repository.
 - The base branch's recorded `upstream_merge_commit`, by SHA.
 
 Export the exact parent-base submodule pointer as `SKIA_SYNC_SKIA_BASE_SHA`; use it instead of a
@@ -58,7 +58,7 @@ DIFF_RANGE="${BASE_UPSTREAM_SHA}..${TARGET_UPSTREAM_REF}"
 ```
 
 Use ancestry, not SHA equality, to determine whether the target is already contained in the
-selected mono/skia base. If it is, stop before branching. A matching milestone number alone is
+selected paired Skia base. If it is, stop before branching. A matching milestone number alone is
 not proof of no work; same-milestone bug-fix commits still count.
 
 ## Phase 02 — analyze behavior, not only signatures

.agents/skills/update-skia/references/phases/04-05-branch-and-merge.md

@@ -20,9 +20,9 @@ The helper fails instead of resetting existing branches or dirty files. On succe
 
 - the parent feature branch starts at `{PARENT_BASE_SHA}`;
 - every recursive submodule matches that parent commit;
-- the mono/skia pointer is verified against `{SKIA_BASE_SHA}` and
+- the paired Skia pointer is verified against `{SKIA_BASE_SHA}` and
   `origin/{SKIA_BASE_BRANCH}`; and
-- the mono/skia feature branch is created from that exact pointer.
+- the paired Skia feature branch is created from that exact pointer.
 
 If either feature branch already exists, stop and inspect its base and commits. Reuse it only when
 it is the intended continuation; never reset or overwrite unrelated work.
@@ -102,7 +102,7 @@ Before committing:
   row names the revision and enabled/commented state actually present in the merged file.
 - Run `git diff --check` and confirm no unresolved paths remain.
 
-Create the required two-parent merge commit. Verify its parents are the selected mono/skia base and
+Create the required two-parent merge commit. Verify its parents are the selected paired Skia base and
 the target upstream commit. Build-driven dependency or C API adaptations belong in later, separate
 commits after their need is proven.
 
@@ -128,7 +128,7 @@ file counts alone.
 
 ## Gate
 
-- Parent and mono/skia feature branches have the resolved bases.
+- Parent and paired Skia feature branches have the resolved bases.
 - The merge commit has exactly two parents.
 - Every fork patch and dependency difference is classified.
 - `audit_fork_patches.py --validate` passes with no provisional decisions.

.agents/skills/update-skia/references/phases/06-07-update-and-build.md

@@ -42,7 +42,7 @@ causes the helper to fail until you:
 A revision-only roll may retain the same semantic version, but still requires the final reviewed
 identity and source evidence. The helper rejects a manifest version bump when that dependency's
 DEPS identity did not change. It is idempotent; rerun it after every final DEPS/native adaptation
-and after the final mono/skia fix commit so the parent records the exact tested state.
+and after the final paired Skia fix commit so the parent records the exact tested state.
 Every tracked registration, including an unchanged legacy entry, must have non-empty
 `version_source` evidence. Backfill missing `skia_dependency` evidence from the hydrated source so
 supported branches become compliant over time without changing semantic versions unnecessarily.
@@ -101,10 +101,10 @@ affected platform's `native/**/build.cake` and must be reported for cross-platfo
 When evidence disproves an earlier dependency or risk conclusion, update
 `skia-dependency-decisions.md`, `skia-breaking-change-analysis.md`, and the validation-review
 disposition together by replacing the provisional entry; do not append a contradictory "final"
-section. Commit each proven post-merge dependency/C API adaptation in mono/skia as a separate
+section. Commit each proven post-merge dependency/C API adaptation in the paired Skia repository as a separate
 explanatory commit.
 
-After every mono/skia adaptation, rerun `audit_fork_patches.py` with the Phase 05 arguments. Fill
+After every paired Skia adaptation, rerun `audit_fork_patches.py` with the Phase 05 arguments. Fill
 new or changed rows and require `--validate` to pass again. Reuse the exact Phase 05
 `python3 "${SKIA_SYNC_SKILL_DIR:-.agents/skills/update-skia}/scripts/audit_fork_patches.py"`
 command rather than searching

.agents/skills/update-skia/references/phases/08-10-bindings-and-tests.md

@@ -114,9 +114,9 @@ rm -f "$ARTIFACT_DIR/test-exit-code.txt"
 ### Final deterministic reconciliation
 
 After the final full solution passes, complete every deterministic gate against the exact tested
-mono/skia tree before moving to Phase 11:
+paired Skia tree before moving to Phase 11:
 
-1. Ensure every post-merge mono/skia adaptation is committed and the worktree is clean.
+1. Ensure every post-merge paired Skia adaptation is committed and the worktree is clean.
 2. From the parent root, run the metadata finalizer:
 
    ```bash
@@ -126,7 +126,7 @@ mono/skia tree before moving to Phase 11:
 
    If it fails, reconcile every `skia-dependency-changes.json` row with checked-out source,
    `cgmanifest.json`, and `skia-dependency-decisions.md`, then rerun until it passes.
-3. Refresh the fork audit against the **current final mono/skia HEAD**:
+3. Refresh the fork audit against the **current final paired Skia HEAD**:
 
    ```bash
    python3 "${SKIA_SYNC_SKILL_DIR:-.agents/skills/update-skia}/scripts/audit_fork_patches.py" \
@@ -144,12 +144,12 @@ mono/skia tree before moving to Phase 11:
 4. Confirm `skia-dependency-changes.json`, `cgmanifest.json`, and
    `skia-dependency-decisions.md` agree on every changed URL/SHA, semantic version, version source,
    and manifest action.
-5. Confirm `skia-fork-patch-audit.md` has no `TODO` and describes the exact current mono/skia HEAD.
+5. Confirm `skia-fork-patch-audit.md` has no `TODO` and describes the exact current paired Skia HEAD.
 6. Commit version, binding, wrapper, test, and submodule changes in the parent.
 7. Verify no build-time side effects or unrelated files are staged.
-8. Verify the parent gitlink equals the mono/skia commit used by the green run.
+8. Verify the parent gitlink equals the paired Skia commit used by the green run.
 
-Any subsequent mono/skia or dependency change invalidates this reconciliation: return to step 1.
+Any subsequent paired Skia or dependency change invalidates this reconciliation: return to step 1.
 Do not read Phase 11 until both commands above pass against final state.
 
 ## Gate
@@ -158,8 +158,8 @@ Do not read Phase 11 until both commands above pass against final state.
 - No required native function lacks a managed decision.
 - Final unfiltered solution passes every host.
 - Every `GpuPolicy`-required backend initializes and executes with zero failures.
-- Parent points to the exact tested mono/skia commit.
+- Parent points to the exact tested paired Skia commit.
 - The deterministic dependency metadata gate passes with source-backed version verification for
   every tracked DEPS change and no version-only manifest drift.
-- `audit_fork_patches.py --validate` passes against final mono/skia HEAD, and every final fork-delta
+- `audit_fork_patches.py --validate` passes against final paired Skia HEAD, and every final fork-delta
   change has one non-contradictory evidence-backed disposition.

.agents/skills/update-skia/references/phases/11-11-ship.md

@@ -9,8 +9,8 @@ template:
 
 | Repository | Head | Base |
 |---|---|---|
-| mono/skia | `{HEAD_BRANCH}` | `{SKIA_BASE_BRANCH}` |
-| mono/SkiaSharp | `{HEAD_BRANCH}` | `{BASE_BRANCH}` |
+| Paired Skia repository | `{HEAD_BRANCH}` | `{SKIA_BASE_BRANCH}` |
+| Current SkiaSharp repository | `{HEAD_BRANCH}` | `{BASE_BRANCH}` |
 
 Cross-link the PRs and include:
 
@@ -55,7 +55,7 @@ PR. Do not call `noop`: a started automation run either completes this contract
 
 Do not merge without explicit approval.
 
-1. Merge mono/skia first.
+1. Merge the paired Skia PR first.
 2. Fetch the resulting commit on `{SKIA_BASE_BRANCH}`.
 3. Update the parent PR's submodule pointer to that branch commit.
 4. Wait for parent CI.

.agents/skills/update-skia/references/typical-changes.md

@@ -2,22 +2,22 @@
 
 | Repository | File | Change |
 |-----------|------|--------|
-| mono/skia | `BUILD.gn` | Merge conflict resolution (most complex) |
-| mono/skia | `DEPS` | Merge conflict resolution |
-| mono/skia | `include/core/SkMilestone.h` | New milestone number (from upstream) |
-| mono/skia | `include/c/sk_types.h` | Enum/type updates, `SK_C_INCREMENT` reset |
-| mono/skia | `src/c/*.cpp` | C API fixes for new C++ APIs |
-| mono/skia | `src/c/sk_enums.cpp` | Enum mapping updates |
-| mono/skia | `src/c/sk_types_priv.h` | Include path + type conversion updates |
-| mono/SkiaSharp | `.gitmodules` | Submodule branch name |
-| mono/SkiaSharp | `externals/skia` | Submodule pointer |
-| mono/SkiaSharp | `scripts/VERSIONS.txt` | All version numbers |
-| mono/SkiaSharp | `cgmanifest.json` | Security tracking |
-| mono/SkiaSharp | `scripts/azure-templates-variables.yml` | CI config (`SKIASHARP_VERSION`) |
-| mono/SkiaSharp | `native/*/build.cake` | Per-platform GN flag updates (check for removed declare_args) |
-| mono/SkiaSharp | `binding/SkiaSharp/SkiaApi.generated.cs` | Regenerated |
-| mono/SkiaSharp | `binding/SkiaSharp/Definitions.cs` | Type definitions, new enums |
-| mono/SkiaSharp | `binding/SkiaSharp/EnumMappings.cs` | Enum mappings |
-| mono/SkiaSharp | `binding/SkiaSharp/GRDefinitions.cs` | GPU type changes |
-| mono/SkiaSharp | `binding/libSkiaSharp.json` | Type config |
-| mono/SkiaSharp | `tests/Tests/SkiaSharp/*.cs` | Test updates |
+| Paired Skia repository | `BUILD.gn` | Merge conflict resolution (most complex) |
+| Paired Skia repository | `DEPS` | Merge conflict resolution |
+| Paired Skia repository | `include/core/SkMilestone.h` | New milestone number (from upstream) |
+| Paired Skia repository | `include/c/sk_types.h` | Enum/type updates, `SK_C_INCREMENT` reset |
+| Paired Skia repository | `src/c/*.cpp` | C API fixes for new C++ APIs |
+| Paired Skia repository | `src/c/sk_enums.cpp` | Enum mapping updates |
+| Paired Skia repository | `src/c/sk_types_priv.h` | Include path + type conversion updates |
+| Current SkiaSharp repository | `.gitmodules` | Submodule branch name |
+| Current SkiaSharp repository | `externals/skia` | Submodule pointer |
+| Current SkiaSharp repository | `scripts/VERSIONS.txt` | All version numbers |
+| Current SkiaSharp repository | `cgmanifest.json` | Security tracking |
+| Current SkiaSharp repository | `scripts/azure-templates-variables.yml` | CI config (`SKIASHARP_VERSION`) |
+| Current SkiaSharp repository | `native/*/build.cake` | Per-platform GN flag updates (check for removed declare_args) |
+| Current SkiaSharp repository | `binding/SkiaSharp/SkiaApi.generated.cs` | Regenerated |
+| Current SkiaSharp repository | `binding/SkiaSharp/Definitions.cs` | Type definitions, new enums |
+| Current SkiaSharp repository | `binding/SkiaSharp/EnumMappings.cs` | Enum mappings |
+| Current SkiaSharp repository | `binding/SkiaSharp/GRDefinitions.cs` | GPU type changes |
+| Current SkiaSharp repository | `binding/libSkiaSharp.json` | Type config |
+| Current SkiaSharp repository | `tests/Tests/SkiaSharp/*.cs` | Test updates |

.agents/skills/update-skia/scripts/audit_fork_patches.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-"""Audit mono/skia fork-patch integrity during Phases 05 and 10.
+"""Audit paired Skia fork-patch integrity during Phases 05 and 10.
 
 The upstream merge may silently drop or alter a fork patch without producing a
 conflict. This helper compares the old and new upstream-relative fork deltas,
@@ -252,7 +252,7 @@ def validate(
 
 def main() -> int:
     parser = argparse.ArgumentParser(
-        description="Audit old and new mono/skia fork deltas and validate dispositions."
+        description="Audit old and new paired Skia fork deltas and validate dispositions."
     )
     parser.add_argument("--skia-root", type=Path, default=Path("externals/skia"))
     parser.add_argument("--old-upstream", required=True)