Erroneous "No timeline event analysis data available for this frame"

I've only noticed this when running an app on debug-mode, not profile-mode

Steps to reproduce:

1. Open performance panel
2. Trigger some event in app that causes a lot of frames to be rendered (e.g. scrolling)
3. In the Frame chart, scroll to the beginning and click on one of the first frames ("Frame A")
4. See message: "No timeline event analysis data available for this frame."
5. Now scroll to the end of the frame chart, and start clicking on the frames there
6. Make your way back to "Frame A" and click on it again. The message is now gone.

Initial selection of frame:

Subsequent selection of frame:

Reproduce the issue in the Flutter DevTools performance panel using debug mode and a frame-heavy action such as scrolling. Compare selecting the first frame before and after navigating through later frames; done when the initial frame shows its timeline event analysis data without requiring other frame selections.

索引モデルが issue の本文から書いたものです。