warning: unused import: `std::mem`
 --> components/script/dom/canvasrenderingcontext2d.rs:5:5
  |
5 | use std::mem;
  |     ^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: unused import: `std::mem::replace`
 --> components/script/dom/htmlscriptelement.rs:9:5
  |
9 | use std::mem::replace;
  |     ^^^^^^^^^^^^^^^^^