If I visit a javadoc page with a Search box, e.g.
https://download.java.net/java/early_access/jdk13/docs/api/
on Linux x86 Chrome, I see a Search box with a "SEARCH:" label outside the box and the word "Search" inside the box. If I use X-windows copy/paste to e.g. paste the word "feature" inside the search box (without clicking on it first) then I see "Searchfeature" and unsurprisingly "No results found".

JBS gets this right. It also has the word "Search" in the Search box and when I paste into it the word disappears and it searches only for my pasted text.