* Reland path volatility tracker (#23063)" (#23220)

This reverts commit fceef3aa.

* allow disabling based on whether deterministic rendering is needed

https://dart.googlesource.com/sdk.git/+log/1f7dd915f40a..0e52b2abe517

2020-12-21 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.12.0-171.0.dev
2020-12-21 dart-luci-ci-builder@dart-ci.iam.gserviceaccount.com Version 2.12.0-170.0.dev

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This reverts commit 205d2b8e.