Adds per-provider information to omnibox UMA logs.

Adds a fairly general structure to omnibox logs that can be used to pass information (that's not per-result information) from providers to the UMA logs.  Right now it's only used to pass whether the asynchronous pass of a provider has finished, but it will probably be used for other things in the future.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/10380007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@137288 0039d316-1c4b-4281-b951-d872f2087c98
void AutocompleteController::DeleteMatch(const AutocompleteMatch& match) {
  DCHECK(match.deletable);
  match.provider->DeleteMatch(match);  // This may synchronously call back to
  ExpireCopiedEntries();
}

void AutocompleteController::DeleteMatch(const AutocompleteMatch& match) {
  DCHECK(match.deletable);
  match.provider->DeleteMatch(match);  // This may synchronously call back to
  ExpireCopiedEntries();
}
