Introduce AppCacheResponseMetadataWriter to support metadata caching.

content/browser/appcache/mock_appcache_storage.h

 // Copyright 2014 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 CONTENT_BROWSER_APPCACHE_MOCK_APPCACHE_STORAGE_H_
 #define CONTENT_BROWSER_APPCACHE_MOCK_APPCACHE_STORAGE_H_
 
 #include <deque>
 #include <map>
 #include <vector>
@@ skipping 54 matching lines @@
                                  bool* found_network_namespace) override;
   void MarkEntryAsForeign(const GURL& entry_url, int64 cache_id) override;
   void MakeGroupObsolete(AppCacheGroup* group,
                          Delegate* delegate,
                          int response_code) override;
   AppCacheResponseReader* CreateResponseReader(const GURL& manifest_url,
                                                int64 group_id,
                                                int64 response_id) override;
   AppCacheResponseWriter* CreateResponseWriter(const GURL& manifest_url,
                                                int64 group_id) override;
+  AppCacheResponseMetadataWriter* CreateResponseMetadataWriter(
+      int64 group_id,
+      int64 response_id) override;
   void DoomResponses(const GURL& manifest_url,
                      const std::vector<int64>& response_ids) override;
   void DeleteResponses(const GURL& manifest_url,
                        const std::vector<int64>& response_ids) override;
 
  private:
   friend class AppCacheRequestHandlerTest;
   friend class AppCacheServiceImplTest;
   friend class AppCacheUpdateJobTest;
   friend class MockAppCacheStorageTest;
@@ skipping 147 matching lines @@
                            StoreExistingGroupExistingCache);
   FRIEND_TEST_ALL_PREFIXES(AppCacheServiceImplTest,
                            DeleteAppCachesForOrigin);
 
   DISALLOW_COPY_AND_ASSIGN(MockAppCacheStorage);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_APPCACHE_MOCK_APPCACHE_STORAGE_H_