Refactor the offline page storage to include client namespace and id.

components/offline_pages/offline_page_metadata_store_impl.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_METADATA_STORE_IMPL_H_
 #define COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_METADATA_STORE_IMPL_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "components/leveldb_proto/proto_database.h"
 #include "components/offline_pages/offline_page_metadata_store.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace offline_pages {
 
 class OfflinePageEntry;
 
-// Implements OfflinePageMetadataStore using leveldb_proto::Protoatabase
+// Implements OfflinePageMetadataStore using leveldb_proto::ProtoDatabase
 // component. Stores metadata of offline pages as serialized protobufs in a
 // LevelDB key/value pairs.
 // Underlying implementation guarantees that all of the method calls will be
 // executed sequentially, and started operations will finish even after the
 // store is already destroyed (callbacks will be called).
 class OfflinePageMetadataStoreImpl : public OfflinePageMetadataStore {
  public:
   OfflinePageMetadataStoreImpl(
       scoped_refptr<base::SequencedTaskRunner> background_task_runner,
       const base::FilePath& database_dir);
   ~OfflinePageMetadataStoreImpl() override;
 
   // OfflinePageMetadataStore implementation:
   void Load(const LoadCallback& callback) override;
   void AddOrUpdateOfflinePage(const OfflinePageItem& offline_page_record,
                               const UpdateCallback& callback) override;
-  void RemoveOfflinePages(const std::vector<int64_t>& bookmark_ids,
+  void RemoveOfflinePages(const std::vector<int64_t>& offline_ids,
                           const UpdateCallback& callback) override;
   void Reset(const ResetCallback& callback) override;
 
  private:
   void LoadContinuation(const LoadCallback& callback, bool success);
   void LoadDone(const LoadCallback& callback,
                 bool success,
                 scoped_ptr<std::vector<OfflinePageEntry>> entries);
   void NotifyLoadResult(const LoadCallback& callback,
                         LoadStatus status,
                         const std::vector<OfflinePageItem>& result);
 
   // Implements the update.
   void UpdateEntries(
       scoped_ptr<leveldb_proto::ProtoDatabase<OfflinePageEntry>::KeyEntryVector>
           entries_to_save,
       scoped_ptr<std::vector<std::string>> keys_to_remove,
       const UpdateCallback& callback);
 
   void UpdateDone(const OfflinePageMetadataStore::UpdateCallback& callback,
                   bool success);
 
   void ResetDone(const ResetCallback& callback, bool success);
 
+  // Called when a database has to be migrated from old bookmark ids
+  // to new offline ids.
+  // TODO: Remove this eventually.

[fgorski, 2016/02/26 19:29:22]

TODO(bburns): ?
Also this is part of an upgrade path, I don't know if we want to remove it ever.

[bburns, 2016/02/27 00:48:19]

Done.  Softened the comment.  Seems like its cruft we'll want to remove in
_sometime_ (e.g. maybe years...)

+  void DatabaseUpdateDone(const OfflinePageMetadataStore::LoadCallback& cb,
+                          LoadStatus status,
+                          const std::vector<OfflinePageItem>& result,
+                          bool success);
+
   scoped_refptr<base::SequencedTaskRunner> background_task_runner_;
   base::FilePath database_dir_;
   scoped_ptr<leveldb_proto::ProtoDatabase<OfflinePageEntry>> database_;
 
   base::WeakPtrFactory<OfflinePageMetadataStoreImpl> weak_ptr_factory_;
 
   FRIEND_TEST_ALL_PREFIXES(OfflinePageMetadataStoreImplTest,
                            LoadCorruptedStore);
   FRIEND_TEST_ALL_PREFIXES(OfflinePageMetadataStoreImplTest,
                            LoadTotallyCorruptedStore);
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageMetadataStoreImpl);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_METADATA_STORE_IMPL_H_