Add the ability to unload the HistoryBackend....

chrome/browser/profile.h

 // 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.
 
 // This class gathers state related to a single user profile.
 
 #ifndef CHROME_BROWSER_PROFILE_H_
 #define CHROME_BROWSER_PROFILE_H_
 
 #include <set>
@@ skipping 173 matching lines @@
   //
   // Although HistoryService is refcounted, this will not addref, and callers
   // do not need to do any reference counting as long as they keep the pointer
   // only for the local scope (which they should do anyway since the browser
   // process may decide to shut down).
   //
   // |access| defines what the caller plans to do with the service. See
   // the ServiceAccessType definition above.
   virtual HistoryService* GetHistoryService(ServiceAccessType access) = 0;
 
+  // Similar to GetHistoryService(), but won't create the history service if it
+  // doesn't already exist.
+  virtual HistoryService* GetHistoryServiceWithoutCreating() = 0;
+
   // Returns the WebDataService for this profile. This is owned by
   // the Profile. Callers that outlive the life of this profile need to be
   // sure they refcount the returned value.
   //
   // |access| defines what the caller plans to do with the service. See
   // the ServiceAccessType definition above.
   virtual WebDataService* GetWebDataService(ServiceAccessType access) = 0;
 
   // Returns the PasswordStore for this profile. This is owned by the Profile.
   virtual PasswordStore* GetPasswordStore(ServiceAccessType access) = 0;
@@ skipping 176 matching lines @@
   virtual VisitedLinkMaster* GetVisitedLinkMaster();
   virtual UserScriptMaster* GetUserScriptMaster();
   virtual SSLHostState* GetSSLHostState();
   virtual net::StrictTransportSecurityState* GetStrictTransportSecurityState();
   virtual ExtensionsService* GetExtensionsService();
   virtual ExtensionDevToolsManager* GetExtensionDevToolsManager();
   virtual ExtensionProcessManager* GetExtensionProcessManager();
   virtual ExtensionMessageService* GetExtensionMessageService();
   virtual FaviconService* GetFaviconService(ServiceAccessType sat);
   virtual HistoryService* GetHistoryService(ServiceAccessType sat);
+  virtual HistoryService* GetHistoryServiceWithoutCreating();
   virtual WebDataService* GetWebDataService(ServiceAccessType sat);
   virtual PasswordStore* GetPasswordStore(ServiceAccessType sat);
   virtual PrefService* GetPrefs();
   virtual TemplateURLModel* GetTemplateURLModel();
   virtual TemplateURLFetcher* GetTemplateURLFetcher();
   virtual DownloadManager* GetDownloadManager();
   virtual void InitThemes();
   virtual void SetTheme(Extension* extension);
   virtual void SetNativeTheme();
   virtual void ClearTheme();
@@ skipping 151 matching lines @@
 #endif
 
 // This struct is used to pass the spellchecker object through the notification
 // SPELLCHECKER_REINITIALIZED. This is used as the details for the notification
 // service.
 struct SpellcheckerReinitializedDetails {
   scoped_refptr<SpellChecker> spellchecker;
 };
 
 #endif  // CHROME_BROWSER_PROFILE_H_