fix: memory leak in integrated browser element handles

[Simon Siefke (SimonSiefke)]

Details

Adding a browser element to chat creates a temporary remote object handle while extracting its details. That handle is never released, so removing the attachment and DOM element leaves the old element state in the browser process.

Change

Release the temporary handle after extraction finishes, including when extraction fails. Preserve the original result or error if the frame disappears during cleanup.

Before

Adding an element to chat, removing the attachment, and removing the DOM element 37 times adds 37 old selected-element state objects.

After

No more selected-element state growth is detected in the same 37-cycle test. Separate WeakRef wrapper growth disappears after garbage collection; unrelated native and string growth remains in the broader diagnostic.

Test Video

Seven element selection, attachment removal, and DOM removal cycles in the integrated browser.

test.mp4

_{AI disclosure: Model: GPT 6 Astra. Worktime: 53 min}

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

Kyle Cutler (@kycutler)

Matched files:

• src/vs/platform/browserView/electron-main/browserViewFrameInspector.ts
• src/vs/platform/browserView/test/electron-main/browserViewFrameInspector.test.ts

Joaquín Ruales (@jruales)

Matched files:

• src/vs/platform/browserView/electron-main/browserViewFrameInspector.ts
• src/vs/platform/browserView/test/electron-main/browserViewFrameInspector.test.ts

[Copilot]

Copilot review overview

🟢 Approval recommended

The cleanup is correctly scoped and comprehensively tested without changing extraction results or errors.

Review effort: Balanced
Findings: None

What changed in this PR

Fixes a remote object handle leak during integrated-browser element extraction.

Changes:

• Releases temporary CDP handles in a failure-safe finally block.
• Adds tests for success, failure, asynchronous extraction, and cleanup errors.

File	Description
browserViewFrameInspector.ts	Releases temporary element handles after extraction.
browserViewFrameInspector.test.ts	Verifies handle lifecycle and error preservation.

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[Dmitriy Vasyura (dmitrivMS)]

Simon Siefke (@SimonSiefke) Thank you!