 
     func drop(db: SQLiteDBConnection) -> Bool {
         log.debug("Dropping all browser tables.")
-        let additional: [(String, Args?)] = [
-            ("DROP TABLE IF EXISTS faviconSites", nil) // We renamed it to match naming convention.
+        let additional = [
+            "DROP TABLE IF EXISTS faviconSites" // We renamed it to match naming convention.
         ]
 
-        let queries: [(String, Args?)] = AllViews.map { ("DROP VIEW IF EXISTS \($0!)", nil) } as [(String, Args?)] +
-                      AllIndices.map { ("DROP INDEX IF EXISTS \($0!)", nil) } as [(String, Args?)] +
-                      AllTables.map { ("DROP TABLE IF EXISTS \($0!)", nil) } as [(String, Args?)] +
+        let queries = AllViews.map { "DROP VIEW IF EXISTS \($0!)" } +
+                      AllIndices.map { "DROP INDEX IF EXISTS \($0!)" } +
+                      AllTables.map { "DROP TABLE IF EXISTS \($0!)" } +
                       additional
 
         return self.run(db, queries: queries)

        let dropTemp = "DROP TABLE \(tmpTable)"

        // Now run these.
        if !self.run(db, queries: [(domains, nil),
                                   (domainIDs, nil),
                                   (updateHistory, nil),
                                   (dropTemp, nil)]) {
            log.error("Unable to migrate domains.")
            return false
        }


        if from < 6 && to >= 6 {
            if !self.run(db, queries: [
                "DROP INDEX IF EXISTS \(IndexVisitsSiteIDDate)",
                "CREATE INDEX IF NOT EXISTS \(IndexVisitsSiteIDIsLocalDate) ON \(TableVisits) (siteID, is_local, date)",
            ]) {
                return false
            }
        }

        if from < 7 && to >= 7 {
            let queries: [String?] = [
                getDomainsTableCreationString(forVersion: to),
                "ALTER TABLE \(TableHistory) ADD COLUMN domain_id INTEGER REFERENCES \(TableDomains)(id) ON DELETE CASCADE",
            ]

            if !self.runValidQueries(db, queries: queries) {
