Removes some dead database code

chrome/browser/history/history_backend.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_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_
 
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 278 matching lines @@
                       bool* success);
   void RemoveDownloads(const std::set<uint32>& ids);
 
   // Segment usage -------------------------------------------------------------
 
   void QuerySegmentUsage(scoped_refptr<QuerySegmentUsageRequest> request,
                          const base::Time from_time,
                          int max_result_count);
   void DeleteOldSegmentData();
 
-  void IncreaseSegmentDuration(const GURL& url,
-                               base::Time time,
-                               base::TimeDelta delta);
-
-  void QuerySegmentDuration(scoped_refptr<QuerySegmentUsageRequest> request,
-                            const base::Time from_time,
-                            int max_result_count);
-
   // Keyword search terms ------------------------------------------------------
 
   void SetKeywordSearchTermsForURL(const GURL& url,
                                    TemplateURLID keyword_id,
                                    const base::string16& term);
 
   void DeleteAllSearchTermsForKeyword(TemplateURLID keyword_id);
 
   void GetMostRecentKeywordSearchTerms(
       scoped_refptr<GetMostRecentKeywordSearchTermsRequest> request,
@@ skipping 590 matching lines @@
 
   // Listens for the system being under memory pressure.
   scoped_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_