The 'search in google' shown in the right-click menu is actually a 'service' offered by the Safari application, and so is not affected by altering the default browser. It can be disabled in System Preferences - Keyboard - Shortcuts - Services but if shown, will always use Safari.
If Chrome has nothing similar - see Chrome: shortcut for "Search With Google"
Oh, wow that makes sense! Thank you for your reply and tips!!
The link you gave is for Lion, but ok -- still props/kudos!!!
I found this Chrome extension:
"Highlight to Search"
allows you search keywords by highlighting instead of typing them into a search box
Not a right-click-menu-option, but OK let's see (...)