How do I close all open tabs in Chrome browser for the iPad?
In the upper right-hand corner of Chrome for iPad is a square with a number in it. That number is the number of tabs open. 


Single click the square-with-number.
It’ll open a “tab overview” page. 
In the upper left hand corner of the “tab overview” page is a “close all” button.
Clicking that button will close all tabs.