Backed out changeset ebafcda56f98 (bug 456910)

Backed out for Tp regression (bug 457288)

toolkit/components/places/src/nsNavHistory.cpp

@@ -794,6 +794,12 @@ nsNavHistory::InitDB(PRInt16 *aMadeChanges)
   rv = mDBConn->ExecuteSimpleSQL(cacheSizePragma);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  // lock the db file
+  // http://www.sqlite.org/pragma.html#pragma_locking_mode
+  rv = mDBConn->ExecuteSimpleSQL(
+    NS_LITERAL_CSTRING("PRAGMA locking_mode = EXCLUSIVE"));
+  NS_ENSURE_SUCCESS(rv, rv);
+
   // moz_places
   if (!tableExists) {
     *aMadeChanges = DB_MIGRATION_CREATED;