Merge 105363 - Tweak omnibox parsing heuristics more:

Merge 105363 - Tweak omnibox parsing heuristics more:
* UNKNOWN inputs with at least one non-host component get displayed as "possible navigations" (by setting |have_what_you_typed_match| true in HistoryURLProvider::DoAutocomplete()).
* Inputs with at least two non-host components (generally) get treated as URLs by AutocompleteInput::Parse().  Technically these could be searches but intranet URLs are much more likely.
* Allow more cases to be REQUESTED_URL, such as "user@host" + ctrl.  I'm not sure these were ever intentionally excluded from the ctrl-enter handling, and I don't see why they should be.

Also use url_parse::ParsePort(), which didn't use to exist (I think?) to replace some code in AutocompleteInput::Parse().

BUG=99131
TEST=Covered by unittests
Review URL: http://codereview.chromium.org/8258004

TBR=pkasting@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=105880