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components/leveldb_proto/proto_database.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_LEVELDB_PROTO_PROTO_DATABASE_H_
 #define COMPONENTS_LEVELDB_PROTO_PROTO_DATABASE_H_
 
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace leveldb_proto {
 
 // Interface for classes providing persistent storage of Protocol Buffer
 // entries (T must be a Proto type extending MessageLite).
 template <typename T>
 class ProtoDatabase {
  public:
   using InitCallback = base::Callback<void(bool success)>;
   using UpdateCallback = base::Callback<void(bool success)>;
   using LoadCallback =
       base::Callback<void(bool success, scoped_ptr<std::vector<T>>)>;
+  using DestroyCallback = base::Callback<void(bool success)>;
 
   // A list of key-value (string, T) tuples.
   using KeyEntryVector = std::vector<std::pair<std::string, T>>;
 
   virtual ~ProtoDatabase() {}
 
   // Asynchronously initializes the object. |callback| will be invoked on the
   // calling thread when complete.
   virtual void Init(const char* client_name,
                     const base::FilePath& database_dir,
                     const InitCallback& callback) = 0;
 
   // Asynchronously saves |entries_to_save| and deletes entries from
   // |keys_to_remove| from the database. |callback| will be invoked on the
   // calling thread when complete.
   virtual void UpdateEntries(
       scoped_ptr<KeyEntryVector> entries_to_save,
       scoped_ptr<std::vector<std::string>> keys_to_remove,
       const UpdateCallback& callback) = 0;
 
   // Asynchronously loads all entries from the database and invokes |callback|
   // when complete.
   virtual void LoadEntries(const LoadCallback& callback) = 0;
+
+  // Asynchronously destroys the database.
+  virtual void Destroy(const DestroyCallback& callback) = 0;
 };
 
 }  // namespace leveldb_proto
 
 #endif  // COMPONENTS_LEVELDB_PROTO_PROTO_DATABASE_H_