[Offline Pages] Removes the unused "HasPages" function.

components/offline_pages/offline_page_model.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 COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_
 #define COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 90 matching lines @@
 
   // Deletes pages based on |offline_ids|.
   virtual void DeletePagesByOfflineId(const std::vector<int64_t>& offline_ids,
                                       const DeletePageCallback& callback) = 0;
 
   // Deletes cached offline pages matching the URL predicate.
   virtual void DeleteCachedPagesByURLPredicate(
       const UrlPredicate& predicate,
       const DeletePageCallback& callback) = 0;
 
-  // Returns true via callback if there are offline pages in the given
-  // |name_space|.
-  virtual void HasPages(const std::string& name_space,
-                        const HasPagesCallback& callback) = 0;
-
   // Returns via callback all GURLs in |urls| that are equal to the online URL
   // of any offline page.
   virtual void CheckPagesExistOffline(
       const std::set<GURL>& urls,
       const CheckPagesExistOfflineCallback& callback) = 0;
 
   // Gets all offline pages.
   virtual void GetAllPages(const MultipleOfflinePageItemCallback& callback) = 0;
 
   // Gets all offline pages including expired ones.
@@ skipping 66 matching lines @@
   // TODO(dougarnett): Remove this and its uses.
   virtual bool is_loaded() const = 0;
 
   // Returns the logger. Ownership is retained by the model.
   virtual OfflineEventLogger* GetLogger() = 0;
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_