Remove last usage functions from HostContentSettingsMap and clean up prefs

chrome/browser/permissions/permission_manager.h

 // Copyright 2015 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_PERMISSIONS_PERMISSION_MANAGER_H_
 #define CHROME_BROWSER_PERMISSIONS_PERMISSION_MANAGER_H_
 
 #include <unordered_map>
 
 #include "base/callback_forward.h"
@@ skipping 54 matching lines @@
           void(const std::vector<blink::mojom::PermissionStatus>&)>& callback)
       override;
   void CancelPermissionRequest(int request_id) override;
   void ResetPermission(content::PermissionType permission,
                        const GURL& requesting_origin,
                        const GURL& embedding_origin) override;
   blink::mojom::PermissionStatus GetPermissionStatus(
       content::PermissionType permission,
       const GURL& requesting_origin,
       const GURL& embedding_origin) override;
-  void RegisterPermissionUsage(content::PermissionType permission,
-                               const GURL& requesting_origin,
-                               const GURL& embedding_origin) override;
   int SubscribePermissionStatusChange(
       content::PermissionType permission,
       const GURL& requesting_origin,
       const GURL& embedding_origin,
       const base::Callback<void(blink::mojom::PermissionStatus)>& callback)
       override;
   void UnsubscribePermissionStatusChange(int subscription_id) override;
 
   // TODO(raymes): Rather than exposing this, expose a denial reason from
   // GetPermissionStatus so that callers can determine whether a permission is
@@ skipping 36 matching lines @@
                      std::unique_ptr<PermissionContextBase>,
                      ContentSettingsTypeHash>
       permission_contexts_;
 
   base::WeakPtrFactory<PermissionManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PermissionManager);
 };
 
 #endif // CHROME_BROWSER_PERMISSIONS_PERMISSION_MANAGER_H_