History of Engine::tick 2 changes

In crates/backdrop/src/lib.rs, lines 107–134 on 8306eca4e4a3347a39de4baeaa83e7c7270fa356998bd66b6923b4338a5d2373. 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.