Introduce per-tab preferences service.

chrome/browser/ui/tab_contents/tab_contents_wrapper.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_WRAPPER_H_
 #define CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_WRAPPER_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 22 matching lines @@
 class ExternalProtocolObserver;
 class FaviconTabHelper;
 class FindTabHelper;
 class InfoBarTabHelper;
 class HistoryTabHelper;
 class NavigationController;
 class OmniboxSearchHint;
 class PasswordManager;
 class PasswordManagerDelegate;
 class PluginObserver;
+class PrefService;
 class Profile;
 class RestoreTabHelper;
 class SadTabObserver;
 class SearchEngineTabHelper;
 class TabContentsSSLHelper;
 class TabContentsWrapperDelegate;
 class TabContentsWrapperSyncedTabDelegate;
 class TabSpecificContentSettings;
 class ThumbnailGenerator;
 class TranslateTabHelper;
@@ skipping 262 matching lines @@
 
   scoped_ptr<TranslateTabHelper> translate_tab_helper_;
 
   // Per-tab observers ---------------------------------------------------------
   // (These provide no API for callers; objects that need to exist 1:1 with tabs
   // and silently do their thing live here.)
 
   scoped_ptr<DownloadRequestLimiterObserver> download_request_limiter_observer_;
   scoped_ptr<ExtensionWebNavigationTabObserver> webnavigation_observer_;
   scoped_ptr<ExternalProtocolObserver> external_protocol_observer_;
+  scoped_ptr<PrefService> per_tab_prefs_; // Allows overriding user preferences.
   scoped_ptr<PluginObserver> plugin_observer_;
   scoped_ptr<printing::PrintPreviewMessageHandler> print_preview_;
   scoped_ptr<SadTabObserver> sad_tab_observer_;
   scoped_ptr<ThumbnailGenerator> thumbnail_generation_observer_;
 
   // TabContents (MUST BE LAST) ------------------------------------------------
 
   // If true, we're running the destructor.
   bool in_destructor_;
 
   // The supporting objects need to outlive the TabContents dtor (as they may
   // be called upon during its execution). As a result, this must come last
   // in the list.
   scoped_ptr<TabContents> tab_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(TabContentsWrapper);
 };
 
 #endif  // CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_WRAPPER_H_