Omnibox: Refactor SearchProvider Utility for Creating Suggestions

Cleanup SearchProvider interfaces to reduce the number of parameters
to CreateSearchSuggestion(), which was bloated while adding support
for entity suggestions in https://codereview.chromium.org/26688004

This is another necessary step for reviving
https://codereview.chromium.org/23164011/

BUG=259486

Review URL: https://codereview.chromium.org/121493006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242919 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242919