[Sync] Add support for performing a GetKey on startup.

sync/util/cryptographer.h

 // Copyright (c) 2012 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 SYNC_UTIL_CRYPTOGRAPHER_H_
 #define SYNC_UTIL_CRYPTOGRAPHER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 161 matching lines @@
   // Update the cryptographer based on the contents of the nigori specifics.
   // This updates both the encryption keys and the set of encrypted types.
   // Returns NEEDS_PASSPHRASE if was unable to decrypt the pending keys,
   // SUCCESS otherwise.
   // Note: will not change the default key. If the nigori's keybag
   // is decryptable, all keys are added to the local keybag and the current
   // default is preserved. If the nigori's keybag is not decryptable, it is
   // stored in the |pending_keys_|.
   UpdateResult Update(const sync_pb::NigoriSpecifics& nigori);
 
+  // Set the keystore-derived nigori from the provided key.
+  // Returns true if we succesfully create the keystore derived nigori from the
+  // provided key, false otherwise.
+  bool SetKeystoreKey(const std::string& keystore_key);
+
+  // Returns true if we currently have a keystore-derived nigori, false
+  // otherwise.
+  bool HasKeystoreKey();
+
   // The set of types that are always encrypted.
   static ModelTypeSet SensitiveTypes();
 
   // Reset our set of encrypted types based on the contents of the nigori
   // specifics.
   void UpdateEncryptedTypesFromNigori(const sync_pb::NigoriSpecifics& nigori);
 
   // Update the nigori to reflect the current set of encrypted types.
   void UpdateNigoriFromEncryptedTypes(sync_pb::NigoriSpecifics* nigori) const;
 
@@ skipping 38 matching lines @@
   // persistence by sync infrastructure.
   bool PackBootstrapToken(const Nigori* nigori, std::string* pack_into) const;
   Nigori* UnpackBootstrapToken(const std::string& token) const;
 
   Encryptor* const encryptor_;
 
   ObserverList<Observer> observers_;
 
   NigoriMap nigoris_;  // The Nigoris we know about, mapped by key name.
   NigoriMap::value_type* default_nigori_;  // The Nigori used for encryption.
+  NigoriMap::value_type* keystore_nigori_; // Nigori generated from keystore.
 
   scoped_ptr<sync_pb::EncryptedData> pending_keys_;
 
   ModelTypeSet encrypted_types_;
   bool encrypt_everything_;
 
   DISALLOW_COPY_AND_ASSIGN(Cryptographer);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_UTIL_CRYPTOGRAPHER_H_