@rvt
I've just experimented, and for me, I can enter a search term, press return, end up at google with the term in the search field on the web page. If I then click on a search result, and press the menu bar back button subsequently, I end up back at google with the search term still in the search entry field.
I don't know why you're not experiencing that behaviour.
While I see this behaviour when I actively look for it, the way I normally use chrome is to middle click on each promising search entry to open them in a new tab, so the original search results sit untouched until I've found what I want.
Hope that's some help.