Interesting. After playing with it a bit I came to the example:

You must not have local noto fonts installed for this to work.

http://codepen.io/anon/pen/dpdOzk

Using chromium we see that:

Inheriting the font means the "bug" doesn't affect you.

Adding a class with the font only affects textareas, not inputs.

Adding the font directly affects both.

Notably the google demonstration page has the rule:

    html,input,textarea{font-family:'noto sans',arial,sans-serif}

this applies the noto bug directly to the input field.