Support mac wpt builds (#29867)

* Add wpt-mac builds

* Fix wpt reporting check run tag

* There can only be five concurrent mac runners

.github/workflows/mac-wpt.yml

@@ -0,0 +1,98 @@
+---
+name: Mac WPT Tests
+on:
+  workflow_call:
+    inputs:
+      layout:
+        required: true
+        type: string
+
+env:
+  RUST_BACKTRACE: 1
+  SHELL: /bin/bash
+
+jobs:
+  mac-wpt:
+    name: WPT ${{ inputs.layout }}
+    runs-on: macos-13
+    env:
+      max_chunk_id: 5
+    strategy:
+      fail-fast: false
+      matrix:
+        chunk_id: [1, 2, 3, 4, 5]
+    steps:
+      - uses: actions/checkout@v3
+        if: github.event_name != 'issue_comment'
+        with:
+          fetch-depth: 2
+      # This is necessary to checkout the pull request if this run was triggered
+      # via an `issue_comment` action on a pull request.
+      - uses: actions/checkout@v3
+        if: github.event_name == 'issue_comment'
+        with:
+          ref: refs/pull/${{ github.event.issue.number }}/head
+          fetch-depth: 2
+      - uses: actions/download-artifact@v3
+        with:
+          name: release-binary-macos
+      - name: Prep test environment
+        run: |
+          gtar -xzf target.tar.gz
+          python3 -m pip install --upgrade pip virtualenv
+          python3 ./mach bootstrap
+      - name: Smoketest
+        run: python3 ./mach smoketest
+      - name: Run tests
+        run: |
+          python3 ./mach test-wpt --with-${{ inputs.layout }} \
+            --release --processes $(sysctl -n hw.logicalcpu) --timeout-multiplier 8 \
+            --total-chunks ${{ env.max_chunk_id }} --this-chunk ${{ matrix.chunk_id }} \
+            --log-raw test-wpt.${{ matrix.chunk_id }}.log \
+            --log-raw-unexpected unexpected-test-wpt.${{ matrix.chunk_id }}.log \
+            --filter-intermittents filtered-test-wpt.${{ matrix.chunk_id }}.json
+      - name: Archive filtered results
+        uses: actions/upload-artifact@v3
+        if: always()
+        with:
+          name: wpt-filtered-results-mac-${{ inputs.layout }}
+          path: |
+            filtered-test-wpt.${{ matrix.chunk_id }}.json
+            unexpected-test-wpt.${{ matrix.chunk_id }}.log
+      - name: Archive logs
+        uses: actions/upload-artifact@v3
+        if: failure()
+        with:
+          name: wpt-logs-mac-${{ inputs.layout }}
+          path: |
+            test-wpt.${{ matrix.chunk_id }}.log
+            filtered-wpt-results.${{ matrix.chunk_id }}.json
+
+  report-test-results:
+    name: Reporting test results
+    runs-on: ubuntu-latest
+    if: ${{ always() && !cancelled() }}
+    needs: [ mac-wpt ]
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 2
+      - uses: actions/download-artifact@v3
+        with:
+          name: wpt-filtered-results-mac-${{ inputs.layout }}
+          path: wpt-filtered-results-mac
+      - name: Create aggregated unexpected results
+        run: cat wpt-filtered-results-mac/*.log > unexpected-test-wpt.log
+      - name: Archive aggregate results
+        uses: actions/upload-artifact@v3
+        with:
+          name: wpt-filtered-results-mac-${{ inputs.layout }}
+          path: |
+            unexpected-test-wpt.log
+      - name: Comment on PR with results
+        run: etc/ci/report_aggregated_expected_results.py --tag="mac-wpt-${{ inputs.layout }}"
+          wpt-filtered-results-mac/*.json
+        env:
+          GITHUB_CONTEXT: ${{ toJson(github) }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          RESULTS: ${{ toJson(needs.*.result) }}