Omnibox: Bug Fixes for Shortcuts Inlining

Precisely, fixes up URL-like inputs before comparing to the shortcuts
fill_into_edit in order to better determine inlineability.

This is especially useful for inputs such as about: which need to have
their scheme fixed up to be recognized as comparable to chrome://
shortcuts.

BUG=328220

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=242029

R=pkasting@chromium.org

Review URL: https://codereview.chromium.org/108643003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242119 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242119