Eliminate the archived history database and clean up related code.

chrome/browser/history/url_database.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 "chrome/browser/history/url_database.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 #include <vector>
@@ skipping 199 matching lines @@
 }
 
 bool URLDatabase::CreateTemporaryURLTable() {
   return CreateURLTable(true);
 }
 
 bool URLDatabase::CommitTemporaryURLTable() {
   // See the comments in the header file as well as
   // HistoryBackend::DeleteAllHistory() for more information on how this works
   // and why it does what it does.
-  //
-  // Note that the main database overrides this to additionally create the
-  // supplimentary indices that the archived database doesn't need.
 
   // Swap the url table out and replace it with the temporary one.
   if (!GetDB().Execute("DROP TABLE urls")) {
     NOTREACHED() << GetDB().GetErrorMessage();
     return false;
   }
   if (!GetDB().Execute("ALTER TABLE temp_urls RENAME TO urls")) {
     NOTREACHED() << GetDB().GetErrorMessage();
     return false;
   }
 
-  // Create the index over URLs. This is needed for the main, in-memory, and
-  // archived databases, so we always do it. The supplimentary indices used by
-  // the main database are not created here. When deleting all history, they
-  // are created by HistoryDatabase::RecreateAllButStarAndURLTables().
+  // Re-create the index over the now permanent URLs table -- this was not there
+  // for the temporary table.
   CreateMainURLIndex();
 
   return true;
 }
 
 bool URLDatabase::InitURLEnumeratorForEverything(URLEnumerator* enumerator) {
   DCHECK(!enumerator->initialized_);
   std::string sql("SELECT ");
   sql.append(kURLRowFields);
   sql.append(" FROM urls");
@@ skipping 362 matching lines @@
       "visit_count INTEGER DEFAULT 0 NOT NULL,"
       "typed_count INTEGER DEFAULT 0 NOT NULL,"
       "last_visit_time INTEGER NOT NULL,"
       "hidden INTEGER DEFAULT 0 NOT NULL,"
       "favicon_id INTEGER DEFAULT 0 NOT NULL)"); // favicon_id is not used now.
 
   return GetDB().Execute(sql.c_str());
 }
 
 bool URLDatabase::CreateMainURLIndex() {
-  // Index over URLs so we can quickly look up based on URL.
   return GetDB().Execute(
       "CREATE INDEX IF NOT EXISTS urls_url_index ON urls (url)");
 }
 
 }  // namespace history