Proof of concept implementation of context based history filtering.

components/history/core/browser/visit_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 COMPONENTS_HISTORY_CORE_BROWSER_VISIT_DATABASE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_VISIT_DATABASE_H_
 
 #include <vector>
 
 #include "components/history/core/browser/history_types.h"
@@ skipping 202 matching lines @@
   // don't have visit_duration column yet.
   bool MigrateVisitsWithoutDuration();
 
  private:
 
   DISALLOW_COPY_AND_ASSIGN(VisitDatabase);
 };
 
 // Rows, in order, of the visit table.
 #define HISTORY_VISIT_ROW_FIELDS \
-    " id,url,visit_time,from_visit,transition,segment_id,visit_duration "
+    " id,url,visit_time,from_visit,transition,segment_id,visit_duration,context "
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_VISIT_DATABASE_H_