[browser] keyboard navigation from url search should populate field

[Bill Filler]

when searching from the url field, we should populate the url field with the search results when using arrow key to navigate the result list.

For example:
1) type pastebin.ub
2) results show me
http://pastebin.ubuntu.com/43434343434
http://pastebin.ubuntu.com/23232323232
3) use the arrow keys to navigate

Expected results:
the url field should be populated with the entry that has been navigated to. The enter button should not be executed so user can modify the url that is in the field

Actual results:
nothing is populated in the url field until a search result is selected, and this executes the search giving user no opportunity to edit the url string