Changing the default google domain in Chrome

On a mac, make sure that you closed the Chrome browser.

Go to

cd ~/Library/Application\ Support/Google/Chrome

and edit the 'Local State' file,
change the following lines to whatever google domain you want.

"last_known_google_url": "http://www.google.com/",
"last_prompted_google_url": "http://www.google.com/",

start the browser.

If you use profiles you have to go to that profile folder and change the 'Local State' file there
cd ~/Library/Application\ Support/Google/Chrome/[PROFILE NAME]