Refactor LoginDatabase migration

components/password_manager/core/browser/login_database.h

Index: components/password_manager/core/browser/login_database.h
diff --git a/components/password_manager/core/browser/login_database.h b/components/password_manager/core/browser/login_database.h
index 47b1a87b429d600ac4e1355e627721c5e67a3b92..934282dabe91d5a4088e6d9aa86459c5d46e92da 100644
--- a/components/password_manager/core/browser/login_database.h
+++ b/components/password_manager/core/browser/login_database.h
@@ -170,9 +170,6 @@ class LoginDatabase {
   static EncryptionResult DecryptedString(const std::string& cipher_text,
                                           base::string16* plain_text);
 
-  bool InitLoginsTable();
-  bool MigrateOldVersionsAsNeeded();
-
   // Fills |form| from the values in the given statement (which is assumed to
   // be of the form used by the Get*Logins methods).
   // Returns the EncryptionResult from decrypting the password in |s|; if not
@@ -207,6 +204,21 @@ class LoginDatabase {
   // crbug.com/466638
   bool clear_password_values_;
 
+  // These cached strings are used to build SQL statements.
+  std::string add_statement_;
+  std::string add_replace_statement_;
+  std::string update_statement_;
+  std::string delete_statement_;
+  std::string autosignin_statement_;
+  std::string get_statement_;
+  std::string get_statement_psl_;
+  std::string get_statement_federated_;
+  std::string get_statement_psl_federated_;
+  std::string created_statement_;
+  std::string synced_statement_;
+  std::string blacklisted_statement_;
+  std::string encrypted_statement_;
+
   DISALLOW_COPY_AND_ASSIGN(LoginDatabase);
 };