Standardize usage of virtual/override/final specifiers in sql/.

sql/transaction_unittest.cc

 // Copyright (c) 2011 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.
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "sql/connection.h"
 #include "sql/statement.h"
 #include "sql/transaction.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/sqlite/sqlite3.h"
 
 class SQLTransactionTest : public testing::Test {
  public:
-  virtual void SetUp() {
+  void SetUp() override {
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
     ASSERT_TRUE(db_.Open(
         temp_dir_.path().AppendASCII("SQLTransactionTest.db")));
 
     ASSERT_TRUE(db().Execute("CREATE TABLE foo (a, b)"));
   }
 
-  virtual void TearDown() {
-    db_.Close();
-  }
+  void TearDown() override { db_.Close(); }
 
   sql::Connection& db() { return db_; }
 
   // Returns the number of rows in table "foo".
   int CountFoo() {
     sql::Statement count(db().GetUniqueStatement("SELECT count(*) FROM foo"));
     count.Step();
     return count.ColumnInt(0);
   }
 
@@ skipping 86 matching lines @@
     EXPECT_EQ(1, db().transaction_nesting());
     {
       sql::Transaction inner3(&db());
       EXPECT_FALSE(inner3.Begin());
       EXPECT_EQ(1, db().transaction_nesting());
     }
   }
   EXPECT_EQ(0, db().transaction_nesting());
   EXPECT_EQ(0, CountFoo());
 }