[Offline Pages] Don't remove user-requested pages when deleting cache.

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 85 matching lines @@
   // will be updated. Requires that the model is loaded.
   virtual void MarkPageAccessed(int64_t offline_id) = 0;
 
   // Wipes out all the data by deleting all saved files and clearing the store.
   virtual void ClearAll(const base::Closure& callback) = 0;
 
   // Deletes pages based on |offline_ids|.
   virtual void DeletePagesByOfflineId(const std::vector<int64_t>& offline_ids,
                                       const DeletePageCallback& callback) = 0;
 
-  // Deletes offline pages matching the URL predicate.
-  virtual void DeletePagesByURLPredicate(
+  // 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.
@@ skipping 74 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_