This is a blog post explaining the process of fixing an issue related to wavy text decorations in Blink, that ended up with a similar fix in WebKit.
Interesting to read about the work and thought-process behind at-first sight “seemingly simple features” such as the wavy underlines for Spelling and Grammar errors. Be sure to also read the two linked posts by Delan if you want to lift the hood up even further.
A story on web engines interoperability related to wavy text decorations →