The text editor that google chrome devtools uses (ClearCode) has vim and emacs modes:
https://codemirror.net/demo/vim.html
https://codemirror.net/demo/emacs.html
Unfortunately there is no way to configure codemirror in chrome without recompiling the browser from source.
Related issue: https://code.google.com/p/chromium/issues/detail?id=249254