Even Firefox' Mobile Awesomebar doesn't do that[1] unless you click that "Yes" button.
On the other hand, Google's Chrome browser is clear about the fact that it does send everything in the omnibar[2]:
> When you type URLs or queries in the Chrome address bar (omnibox) or App Launcher search box, the letters you type may be sent to your default search engine so that the search engine’s prediction feature can automatically recommend terms or URLs you may be looking for.
If you still believe you are right, I would be interested in seeing your sources.
[0]: https://support.mozilla.org/en-US/kb/awesome-bar-find-your-b...
[1]: https://blog.mozilla.org/privacy/2013/01/08/search-suggestio...
Obviously, I can't prove that it doesn't send search suggestions by giving you a link to the code, since it isn't there. If you want to make sure for yourself, I advise using Wireshark.
