Allow embedder to use custom cryptography in Autofill table.

components/autofill/core/browser/webdata/autofill_table_encryptor.h

+// Copyright 2017 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_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_TABLE_ENCRYPTOR_H_
+#define COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_TABLE_ENCRYPTOR_H_
+
+#include <string>
+
+#include "base/strings/string16.h"
+
+namespace autofill {
+// Encryptor used by Autofill table.
+class AutofillTableEncryptor {
+ public:
+  virtual ~AutofillTableEncryptor() = default;
+
+  virtual bool EncryptString16(const base::string16& plaintext,
+                               std::string* ciphertext) const = 0;
+  virtual bool DecryptString16(const std::string& ciphertext,
+                               base::string16* plaintext) const = 0;
+};
+
+}  // namespace autofill
+
+#endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_WEBDATA_AUTOFILL_TABLE_ENCRYPTOR_H_