Probably safe to ignore, just reporting "just in case"
FWIW, this is apparently caused by Chrome now having that chrome://flags/#enable-asm-webassembly enabled by default.
Experimental Validate Asm.js and convert to WebAssembly when valid. Mac, Windows, Linux, Chrome OS, Android
Validate Asm.js when "use asm" is present and then convert to WebAssembly. #enable-asm-webassembly
Disabling it makes the message go away.