Replace HistoryQuickProvider protobuf-based caching with an SQLite-based database.

chrome/browser/autocomplete/history_quick_provider.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/autocomplete/history_quick_provider.h"
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
@@ skipping 129 matching lines @@
       std::string name = "HistoryQuickProvider.QueryIndexTime." +
           base::IntToString(input.text().length());
       base::Histogram* counter = base::Histogram::FactoryGet(
           name, 1, 1000, 50, base::Histogram::kUmaTargetedHistogramFlag);
       counter->Add(static_cast<int>((end_time - start_time).InMilliseconds()));
     }
     UpdateStarredStateOfMatches();
   }
 }
 
-// TODO(mrossetti): Implement this function. (Will happen in next CL.)
-void HistoryQuickProvider::DeleteMatch(const AutocompleteMatch& match) {}
+void HistoryQuickProvider::DeleteMatch(const AutocompleteMatch& match) {
+  DCHECK(match.deletable);
+  DCHECK(match.destination_url.is_valid());
+  // Delete the match from the InMemoryURLIndex.
+  GetIndex()->DeleteURL(match.destination_url);
+  DeleteMatchFromMatches(match);
+}
 
 HistoryQuickProvider::~HistoryQuickProvider() {}
 
 void HistoryQuickProvider::DoAutocomplete() {
   // Get the matching URLs from the DB.
   string16 term_string = autocomplete_input_.text();
   ScoredHistoryMatches matches = GetIndex()->HistoryItemsForTerms(term_string);
   if (matches.empty())
     return;
 
@@ skipping 126 matching lines @@
     do {
       offset += matches[i].length;
       ++i;
     } while ((i < match_count) && (offset == matches[i].offset));
     if (offset < text_length)
       spans.push_back(ACMatchClassification(offset, url_style));
   }
 
   return spans;
 }