Add the ability to unload the HistoryBackend....

chrome/browser/cocoa/history_menu_bridge.mm

 // 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 "chrome/browser/cocoa/history_menu_bridge.h"
 #include "base/sys_string_conversions.h"
 #include "base/string_util.h"
 #include "chrome/app/chrome_dll_resource.h"  // IDC_HISTORY_MENU
 #import "chrome/browser/app_controller_mac.h"
 #import "chrome/browser/cocoa/history_menu_cocoa_controller.h"
@@ skipping 30 matching lines @@
       tab_restore_service_(NULL),
       create_in_progress_(false),
       need_recreate_(false) {
   // If we don't have a profile, do not bother initializing our data sources.
   // This shouldn't happen except in unit tests.
   if (profile_) {
     // Check to see if the history service is ready. Because it loads async, it
     // may not be ready when the Bridge is created. If this happens, register
     // for a notification that tells us the HistoryService is ready.
     HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
-    if (hs != NULL && hs->backend_loaded()) {
+    if (hs != NULL && hs->BackendLoaded()) {
       history_service_ = hs;
       Init();
     }
 
     // TODO(???): NULL here means we're OTR. Show this in the GUI somehow?
     tab_restore_service_ = profile_->GetTabRestoreService();
     if (tab_restore_service_)
       tab_restore_service_->AddObserver(this);
   }
 
@@ skipping 21 matching lines @@
 }
 
 void HistoryMenuBridge::Observe(NotificationType type,
                                 const NotificationSource& source,
                                 const NotificationDetails& details) {
   // A history service is now ready. Check to see if it's the one for the main
   // profile. If so, perform final initialization.
   if (type == NotificationType::HISTORY_LOADED) {
     HistoryService* hs =
         profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
-    if (hs != NULL && hs->backend_loaded()) {
+    if (hs != NULL && hs->BackendLoaded()) {
       history_service_ = hs;
       Init();
 
       // Found our HistoryService, so stop listening for this notification.
       registrar_.Remove(this,
                         NotificationType::HISTORY_LOADED,
                         NotificationService::AllSources());
     }
   }
 
@@ skipping 204 matching lines @@
       entry.navigations.at(entry.current_navigation_index);
   if (current_navigation.url() == GURL(chrome::kChromeUINewTabURL))
     return false;
 
   HistoryItem item;
   item.title = current_navigation.title();
   item.url = current_navigation.url();
   closed_results_.push_back(item);
   return true;
 }