Steps to reproduce:
1. Capture timeline data in 1st level inspector
2. Open 2nd level inspector
3. Show DOM tree in 2nd level inspector
4. Zoom or otherwise change timeline record positions in 1st level inspector
It will take several seconds for the frontend to catch up.
I am not sure what the bottleneck is. We may need a more robust backoff/coalescing approach to fetching attributes. It appears that DOMTreeManager simply coalesces with a 0-delay timer before fetching.
This is so bad inspecting a cnn.com recording that inspector^2 simply hangs.