Remove dependency of PrefSyncableService on PrefsTabHelper.

chrome/browser/ui/prefs/prefs_tab_helper.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.
 
 #ifndef CHROME_BROWSER_UI_PREFS_PREFS_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_PREFS_PREFS_TAB_HELPER_H_
 
 #include "base/callback_list.h"
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 13 matching lines @@
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 // Per-tab class to handle user preferences.
 class PrefsTabHelper : public content::NotificationObserver,
                        public content::WebContentsUserData<PrefsTabHelper> {
  public:
   ~PrefsTabHelper() override;
 
-  static void InitIncognitoUserPrefStore(OverlayUserPrefStore* pref_store);
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
   static void GetServiceInstance();
 
  protected:
   // Update the RenderView's WebPreferences. Exposed as protected for testing.
   virtual void UpdateWebPreferences();
 
  private:
   explicit PrefsTabHelper(content::WebContents* contents);
   friend class content::WebContentsUserData<PrefsTabHelper>;
@@ skipping 16 matching lines @@
   scoped_ptr<base::CallbackList<void(void)>::Subscription>
       style_sheet_subscription_;
   scoped_ptr<ChromeZoomLevelPrefs::DefaultZoomLevelSubscription>
       default_zoom_level_subscription_;
   base::WeakPtrFactory<PrefsTabHelper> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefsTabHelper);
 };
 
 #endif  // CHROME_BROWSER_UI_PREFS_PREFS_TAB_HELPER_H_