chore(highlight): resolve highlights periodically in HighlightController

[Dmitry Gozman (dgozman)]

Summary

• Each page has a HighlightController that keeps the list of highlighted selectors and re-resolves them across frames once a second, so highlights survive navigations, newly attached frames and DOM changes.
• Highlights can optionally pierce frames; the recorder uses this for user-typed selectors and aria templates, restoring cross-frame highlighting ([Feature]: locators in iframes not getting highlighted in Chromium or any browser #33146).
• Frame.addHighlight/removeHighlight/hideHighlight and Page.hideHighlight are replaced by HighlightController methods.
• The injected script renders highlights through a single setHighlights() call per frame that replaces all element highlights at once.
• The pierce/noDefaultPierce selector resolution options are merged into a single tri-state pierce option.

[github-actions]

Test results for "MCP"

2 failed
❌ [chromium] › mcp/cli-killall.spec.ts:42 › kill-all kills filtered dashboard pid @mcp-ubuntu-latest-chromium
❌ [firefox] › mcp/cli-devtools.spec.ts:84 › request shows full request and response details @mcp-windows-latest-firefox

8099 passed, 1311 skipped

---

Merge workflow run.

[github-actions]

Test results for "tests 1"

23 flaky

⚠️ [chromium-library] › library/global-fetch.spec.ts:293 › should return security details from response `@frozen-time-library-chromium-linux`
⚠️ [chromium-library] › library/har.spec.ts:639 › should have security details `@frozen-time-library-chromium-linux`
⚠️ [chromium-library] › library/chromium/chromium.spec.ts:301 › should report intercepted service worker requests in HAR `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/global-fetch.spec.ts:293 › should return security details from response `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/har.spec.ts:639 › should have security details `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/global-fetch.spec.ts:293 › should return security details from response `@realtime-time-library-chromium-linux`
⚠️ [chromium-library] › library/har.spec.ts:639 › should have security details `@realtime-time-library-chromium-linux`
⚠️ [chromium-library] › library/chromium/chromium.spec.ts:436 › should produce network events, routing, and annotations for Service Worker (advanced) `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/global-fetch.spec.ts:293 › should return security details from response `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/har.spec.ts:639 › should have security details `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/chromium/chromium.spec.ts:436 › should produce network events, routing, and annotations for Service Worker (advanced) `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/global-fetch.spec.ts:293 › should return security details from response `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/har.spec.ts:639 › should have security details `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/video.spec.ts:495 › screencast › should capture static page in persistent context Radoslav Kirilov (@smoke) `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/global-fetch.spec.ts:293 › should return security details from response `@chromium-ubuntu-22.04-node22`
⚠️ [chromium-library] › library/har.spec.ts:639 › should have security details `@chromium-ubuntu-22.04-node22`
⚠️ [firefox-library] › library/global-fetch.spec.ts:293 › should return security details from response `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-library] › library/har.spec.ts:639 › should have security details `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-library] › library/heap.spec.ts:223 › should not leak workers `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-page] › page/page-emulate-media.spec.ts:144 › should keep reduced motion and color emulation after reload `@firefox-ubuntu-22.04-node20`
⚠️ [webkit-library] › library/global-fetch.spec.ts:293 › should return security details from response `@webkit-ubuntu-22.04-node20`
⚠️ [webkit-library] › library/har.spec.ts:639 › should have security details `@webkit-ubuntu-22.04-node20`
⚠️ [webkit-page] › page/page-network-request.spec.ts:288 › should parse the data if content-type is application/x-www-form-urlencoded `@webkit-ubuntu-22.04-node20`

51122 passed, 1220 skipped

---

Merge workflow run.

[github-actions]

Hi, I'm the Playwright bot and I took a first look at the CI failures here.

🟢 CI is clear — both failures are pre-existing flakes

The two red MCP tests both flip verdict across hundreds of unrelated runs, and neither exercises anything this PR touches (highlights, frame selectors, screenshotter). Nothing to fix here.

Details

This PR reworks highlight rendering (HighlightController, injected highlight.ts, frameSelectors, pierce option). The only real failures are two MCP CLI tests that don't touch any of that code path.

Pre-existing flake / infra

• [chromium] › mcp/cli-killall.spec.ts:42 › kill-all kills filtered dashboard pid (@mcp-ubuntu-latest-chromium) — established flake. On this exact bot it failed 6 of 729 runs and passed the rest, flipping across SHAs unrelated to this PR (chromium overall: 9 failed / 721 passed). It's a process-kill/PID-filter test, untouched by the highlight changes.

• [firefox] › mcp/cli-devtools.spec.ts:84 › request shows full request and response details (@mcp-windows-latest-firefox) — established flake. On this exact bot it failed 8 of 558 runs and passed the rest, flipping across unrelated SHAs (firefox overall: 5 failed / 718 passed). It asserts on request/response detail output, unrelated to highlighting.

The "tests 1" report shows only flaky/rescued results (0 real failures), so there's nothing else to triage.

_{Triaged by the Playwright bot - agent run}