Part 6 of search provider refactoring.

Part 6 of search provider refactoring.

Makes changes to how the state is recorded in zero_suggest_provider
to facilitate moving out ParseSuggestResults into super class.

Replaces navigation_results_, query_matches_map_, and
verbatim_relevance_ objects with a Results results_ instance. The latter
keeps track of navigation_results_ and query_results_ and constructs
the query matches map on when it's needed.

verbatim_relevance_ in the old code is only used to see the current url
match (based on the server relevance returned in the previous request
or a static value). The new code keeps track of the server verbatim
relevance in results_ and uses an accessor to get either server results
or a constant value if no server results are available, matching the
old semantics.

Merged FillResults with ParseSuggestResults function and moved match
map creation code into ConvertResultsToAutocompleteMatches where it's
used.

BUG=338955
TBR=mpearson

Review URL: https://codereview.chromium.org/171323002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252206 0039d316-1c4b-4281-b951-d872f2087c98