History of Engine::tick 2 changes

In crates/backdrop/src/lib.rs, lines 107–134 on a6d824c5ebf565d6c29e00acb4f646d80640a7810e3eda0c6953099ec4adb9a0. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 107,134:crates/backdrop/src/lib.rs.