As per web news sources we got to know that, Google is testing a “back to top” button in the mobile search interface. This will be really helpful and easy for user to navigate to top mainly if you are searching 100 records results per page 🙂
No need to panic, just on lick and back to search text box.
As reported UI for this button is blue and looks good with white text floats over the bottom portion of on your mobile devices.