Eliminate NOTIFICATION_HISTORY_LOADED notification

chrome/browser/history/in_memory_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.
 
 // The InMemoryHistoryBackend is a wrapper around the in-memory URL database.
 // It maintains an in-memory cache of a subset of history that is required for
 // low-latency operations, such as in-line autocomplete.
 //
 // The in-memory cache provides the following guarantees:
 //  (1.) It will always contain URLRows that either have a |typed_count| > 0; or
 //       that have a corresponding search term, in which case information about
 //       the search term is also stored.
 //  (2.) It will be an actual subset, i.e., it will contain verbatim data, and
 //       will never contain more data that can be found in the main database.
 //
 // The InMemoryHistoryBackend is created on the history thread and passed to the
 // main thread where operations can be completed synchronously. It listens for
 // notifications from the "regular" history backend and keeps itself in sync.
 
 #ifndef CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/scoped_observer.h"
 #include "components/history/core/browser/history_service_observer.h"
 #include "components/history/core/browser/keyword_id.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
 class HistoryService;
 class Profile;
 
 namespace base {
 class FilePath;
@@ skipping 64 matching lines @@
   // Handler for HISTORY_KEYWORD_SEARCH_TERM_DELETED.
   void OnKeywordSearchTermDeleted(const KeywordSearchDeletedDetails& details);
 
   content::NotificationRegistrar registrar_;
 
   scoped_ptr<InMemoryDatabase> db_;
 
   // The profile that this object is attached. May be NULL before
   // initialization.
   Profile* profile_;
+  ScopedObserver<HistoryService, HistoryServiceObserver>
+      history_service_observer_;
   HistoryService* history_service_;
 
   DISALLOW_COPY_AND_ASSIGN(InMemoryHistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_