Add the ability to unload the HistoryBackend....

chrome/browser/autocomplete/autocomplete_edit_view_browsertest.cc

 // Copyright (c) 2009 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 <stdio.h>
 
 #include "base/file_path.h"
 #include "base/keyboard_codes.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ skipping 186 matching lines @@
     model->Add(template_url);
     model->SetDefaultSearchProvider(template_url);
   }
 
   void SetupHistory() {
     Profile* profile = browser()->profile();
     HistoryService* history_service =
         profile->GetHistoryService(Profile::EXPLICIT_ACCESS);
     ASSERT_TRUE(history_service);
 
-    if (!history_service->backend_loaded()) {
+    if (!history_service->BackendLoaded()) {
       NotificationRegistrar registrar;
       registrar.Add(this, NotificationType::HISTORY_LOADED,
                     Source<Profile>(profile));
       ui_test_utils::RunMessageLoop();
     }
 
     BookmarkModel* bookmark_model = profile->GetBookmarkModel();
     ASSERT_TRUE(bookmark_model);
 
     if (!bookmark_model->IsLoaded()) {
@@ skipping 322 matching lines @@
       break;
   }
 
   EXPECT_NE(old_text, edit_view->GetText());
 
   // Escape shall revert back to the default match item.
   ASSERT_NO_FATAL_FAILURE(SendKey(base::VKEY_ESCAPE, false, false, false));
   EXPECT_EQ(old_text, edit_view->GetText());
   EXPECT_EQ(old_selected_line, popup_model->selected_line());
 }