Eliminate the archived history database and clean up related code.

chrome/browser/history/history_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_HISTORY_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_DATABASE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
@@ skipping 120 matching lines @@
   // unused space in the file. It can be VERY SLOW.
   void Vacuum();
 
   // 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);
 
   // Razes the database. Returns true if successful.
   bool Raze();
 
-  // Returns true if the history backend should erase the full text search
-  // and archived history files as part of version 16 -> 17 migration. The
-  // time format changed in this revision, and these files would be much slower
-  // to migrate. Since the data is less important, they should be deleted.
-  //
-  // This flag will be valid after Init() is called. It will always be false
-  // when running on Windows.
-  bool needs_version_17_migration() const {
-    return needs_version_17_migration_;
-  }
-
   // Visit table functions ----------------------------------------------------
 
   // Update the segment id of a visit. Return true on success.
   bool SetSegmentID(VisitID visit_id, SegmentID segment_id);
 
   // Query the segment ID for the provided visit. Return 0 on failure or if the
   // visit id wasn't found.
   SegmentID GetSegmentID(VisitID visit_id);
 
   // Retrieves/Updates early expiration threshold, which specifies the earliest
@@ skipping 31 matching lines @@
 #endif
 
   // ---------------------------------------------------------------------------
 
   sql::Connection::ErrorCallback error_callback_;
   sql::Connection db_;
   sql::MetaTable meta_table_;
 
   base::Time cached_early_expiration_threshold_;
 
-  // See the getters above.
-  bool needs_version_17_migration_;
-
   DISALLOW_COPY_AND_ASSIGN(HistoryDatabase);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_DATABASE_H_