Delete and try to recreate localstorage database on invalid schema version.

components/leveldb/public/interfaces/leveldb.mojom

Index: components/leveldb/public/interfaces/leveldb.mojom
diff --git a/components/leveldb/public/interfaces/leveldb.mojom b/components/leveldb/public/interfaces/leveldb.mojom
index cf62f675f90266d1c6bd92c97ccd0a2ae41ff258..11e567095539380e24698d9627911316ebeaddd2 100644
--- a/components/leveldb/public/interfaces/leveldb.mojom
+++ b/components/leveldb/public/interfaces/leveldb.mojom
@@ -62,15 +62,25 @@ struct OpenOptions {
 
 // Service which hands out databases.
 interface LevelDBService {
+  // Open the database with the specified "name" in the specified "directory".
+  // Fails if the database doesn't already exist.
   Open(filesystem.mojom.Directory directory,
        string dbname,
-       LevelDBDatabase& database) => (DatabaseError status);
+       associated LevelDBDatabase& database) => (DatabaseError status);
+
+  // Open the database with the specified "name" in the specified "directory".
   OpenWithOptions(OpenOptions options,
                   filesystem.mojom.Directory directory,
                   string dbname,
-                  LevelDBDatabase& database) => (DatabaseError status);
+                  associated LevelDBDatabase& database) => (DatabaseError status);
+
+  // Opens a database stored purely in memory.
+  OpenInMemory(associated LevelDBDatabase& database) => (DatabaseError status);
 
-  OpenInMemory(LevelDBDatabase& database) => (DatabaseError status);
+  // Destroys the contents of the specified database. Returns OK if the database
+  // already didn't exist.
+  Destroy(filesystem.mojom.Directory directory,
+          string dbname) => (DatabaseError status);
 };
 
 // A leveldb database.