Eliminate the archived history database and clean up related code.

chrome/browser/history/archived_database.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 CHROME_BROWSER_HISTORY_ARCHIVED_DATABASE_H_
-#define CHROME_BROWSER_HISTORY_ARCHIVED_DATABASE_H_
-
-#include "base/basictypes.h"
-#include "chrome/browser/history/url_database.h"
-#include "chrome/browser/history/visit_database.h"
-#include "sql/connection.h"
-#include "sql/init_status.h"
-#include "sql/meta_table.h"
-
-namespace base {
-class FilePath;
-}
-
-namespace history {
-
-// Encapsulates the database operations for archived history.
-//
-// IMPORTANT NOTE: The IDs in this system for URLs and visits will be
-// different than those in the main database. This is to eliminate the
-// dependency between them so we can deal with each one on its own.
-class ArchivedDatabase : public URLDatabase,
-                         public VisitDatabase {
- public:
-  // Must call Init() before using other members.
-  ArchivedDatabase();
-  virtual ~ArchivedDatabase();
-
-  // Initializes the database connection. This must return true before any other
-  // functions on this class are called.
-  bool Init(const base::FilePath& file_name);
-
-  // Try to trim the cache memory used by the database.  If |aggressively| is
-  // true try to trim all unused cache, otherwise trim by half.
-  void TrimMemory(bool aggressively);
-
-  // Transactions on the database. We support nested transactions and only
-  // commit when the outermost one is committed (sqlite doesn't support true
-  // nested transactions).
-  void BeginTransaction();
-  void CommitTransaction();
-
-  // Returns the current version that we will generate archived databases with.
-  static int GetCurrentVersion();
-
- private:
-  bool InitTables();
-
-  // Implemented for the specialized databases.
-  virtual sql::Connection& GetDB() OVERRIDE;
-
-  // Makes sure the version is up-to-date, updating if necessary. If the
-  // database is too old to migrate, the user will be notified. In this case, or
-  // for other errors, false will be returned. True means it is up-to-date and
-  // ready for use.
-  //
-  // This assumes it is called from the init function inside a transaction. It
-  // may commit the transaction and start a new one if migration requires it.
-  sql::InitStatus EnsureCurrentVersion();
-
-  // The database.
-  sql::Connection db_;
-  sql::MetaTable meta_table_;
-
-  DISALLOW_COPY_AND_ASSIGN(ArchivedDatabase);
-};
-
-}  // namespace history
-
-#endif  // CHROME_BROWSER_HISTORY_ARCHIVED_DATABASE_H_