Large number of event.meta.bounds is undefined errors when viewing timeline

[ijdickinson]

Version

6.0.0-beta.7

Browser and OS info

Firefox 87.0 / Ubuntu 20.10

Steps to reproduce

1. Launch Vue 3 app
2. Open devtools
3. Select Timeline tool
4. Select a component event from the timeline to view details of
5. Track mouse across the timeline

What is expected?

No console errors

What is actually happening?

Many (i.e. hundreds) of events on the console. See below for example stacktrace.

After this starts happening, dev-tools seems to be in a confused state. I have to close the dev-tools window and the tab with my app in it to get back to a normal state

---

TypeError: event.meta.bounds is undefined
    screenshotOverlayRender moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:3533
    showScreenshot moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:3401
    run moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:4373
    queue moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:4379
    queue moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:4362
    showScreenshot moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:3376
    connect moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:846
    emit moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:3720
    _emit moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:1126
    Bridge moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:1058
    Bridge moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:1058
    listener moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:2105
    listen moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:2108
    Bridge moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:1056
    handshake moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:2101
    282 moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:2086
    __webpack_require__ moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:20
    <anonymous> moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:84
    <anonymous> moz-extension://68ba6716-e5fe-4cc1-b580-6a6d6f466c26/build/backend.js:87
backend.js:3412:33