Replace FTS in the history_service with a brute force text search.

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 611 matching lines @@
   // When a simple GetMostRecentRedirectsFrom() fails, this method is
   // called which searches the last N visit sessions instead of just
   // the current one. Returns true and puts thumbnail data in |data|
   // if a proper thumbnail was found. Returns false otherwise. Assumes
   // that this HistoryBackend object has been Init()ed successfully.
   bool GetThumbnailFromOlderRedirect(
       const GURL& page_url, std::vector<unsigned char>* data);
 
   // Querying ------------------------------------------------------------------
 
-  // Backends for QueryHistory. *Basic() handles queries that are not FTS (full
-  // text search) queries and can just be given directly to the history DB).
-  // The FTS version queries the text_database, then merges with the history DB.
+  // Backends for QueryHistory. *Basic() handles queries that are not
+  // text search queries and can just be given directly to the history DB.
+  // The *Text() version performs a brute force query of the history DB to
+  // search for results which match the given text query.
   // Both functions assume QueryHistory already checked the DB for validity.
   void QueryHistoryBasic(URLDatabase* url_db, VisitDatabase* visit_db,
                          const QueryOptions& options, QueryResults* result);
+  void QueryHistoryText(URLDatabase* url_db,
+                        VisitDatabase* visit_db,
+                        const string16& text_query,
+                        const QueryOptions& options,
+                        QueryResults* result);
   void QueryHistoryFTS(const string16& text_query,
                        const QueryOptions& options,
                        QueryResults* result);
 
   // Committing ----------------------------------------------------------------
 
   // We always keep a transaction open on the history database so that multiple
   // transactions can be batched. Periodically, these are flushed (use
   // ScheduleCommit). This function does the commit to write any new changes to
   // disk and opens a new transaction. This will be called automatically by
@@ skipping 266 matching lines @@
   // Used to manage syncing of the typed urls datatype. This will be NULL
   // before Init is called.
   scoped_ptr<TypedUrlSyncableService> typed_url_syncable_service_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_BACKEND_H_