Maybe the clipboard provider should tell the clipboard to "age out" (mark unsuitable for omnibox suggestion) entries that aren't selected when displayed to users, under the assumption users weren't trying to load them after all.

This could limit the annoyingness of irrelevant or private suggestions; if I copy a URL, then I believe the current code will keep showing me that URL on every focus for the next hour.

OTOH, there are reasons why I might do some omnibox interactions before navigating to the URL in question, so perhaps aging out after one appearance is too aggressive.  if this provider gets used, maybe we should histogram "how many times was the URL shown before being used".

Filing as ZeroSuggest even though it's kinda technically not.  Feel free to move.