Prevents the shortcuts DB from going out of scope before unittests run.

components/omnibox/browser/shortcuts_database_unittest.cc

 // 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.
 
 #include "components/omnibox/browser/shortcuts_database.h"
 
 #include <stddef.h>
 
 #include "base/files/scoped_temp_dir.h"
 #include "base/format_macros.h"
@@ skipping 78 matching lines @@
   void TearDown() override;
 
   void ClearDB();
   size_t CountRecords() const;
 
   ShortcutsDatabase::Shortcut ShortcutFromTestInfo(
       const ShortcutsDatabaseTestInfo& info);
 
   void AddAll();
 
+  base::ScopedTempDir temp_dir_;
   scoped_refptr<ShortcutsDatabase> db_;
 };
 
 void ShortcutsDatabaseTest::SetUp() {
-  base::ScopedTempDir temp_dir;
-  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
-  base::FilePath db_path(temp_dir.path().Append(kShortcutsDatabaseName));
+  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+  base::FilePath db_path(temp_dir_.path().Append(kShortcutsDatabaseName));
   db_ = new ShortcutsDatabase(db_path);
   ASSERT_TRUE(db_->Init());
   ClearDB();
 }
 
 void ShortcutsDatabaseTest::TearDown() {
   db_ = NULL;
 }
 
 void ShortcutsDatabaseTest::ClearDB() {
@@ skipping 247 matching lines @@
   // recovered.
   {
     sql::Connection connection;
     ASSERT_TRUE(connection.Open(db_path));
     sql::Statement statement(connection.GetUniqueStatement(kCountSql));
     ASSERT_TRUE(statement.is_valid());
     ASSERT_TRUE(statement.Step());
     EXPECT_EQ(row_count, statement.ColumnInt(0));
   }
 }