Implement the renderer side of the mojo based local storage implementation.

content/renderer/dom_storage/local_storage_cached_areas.h

 // Copyright 2016 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_RENDERER_DOM_STORAGE_LOCAL_STORAGE_CACHED_AREAS_H_
 #define CONTENT_RENDERER_DOM_STORAGE_LOCAL_STORAGE_CACHED_AREAS_H_
 
 #include <map>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "url/origin.h"
 
 namespace content {
 class LocalStorageCachedArea;
 class StoragePartitionService;
 
-// Owns all the LocalStorageCachedArea objects in a renderer. This is needed
-// because we can have n LocalStorageArea objects for the same origin but we
-// want just one LocalStorageCachedArea to service them (no point in having
+// Keeps a map of all the LocalStorageCachedArea objects in a renderer. This is
+// needed because we can have n LocalStorageArea objects for the same origin but
+// we want just one LocalStorageCachedArea to service them (no point in having
 // multiple caches of the same data in the same process).
 class LocalStorageCachedAreas {
  public:
   explicit LocalStorageCachedAreas(
       StoragePartitionService* storage_partition_service);
   ~LocalStorageCachedAreas();
 
-  scoped_refptr<LocalStorageCachedArea> GetLocalStorageCachedArea(
-      const url::Origin& origin);
+  // Returns, creating if necessary, a cached storage area for the given origin.
+  scoped_refptr<LocalStorageCachedArea>
+      GetCachedArea(const url::Origin& origin);
 
   // Called by LocalStorageCachedArea on destruction.
-  void LocalStorageCacheAreaClosed(LocalStorageCachedArea* cached_area);
+  void CacheAreaClosed(LocalStorageCachedArea* cached_area);
 
  private:
   StoragePartitionService* const storage_partition_service_;
 
   // Maps from an origin to its LocalStorageCachedArea object. The object owns
   // itself.
   std::map<url::Origin, LocalStorageCachedArea*> cached_areas_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalStorageCachedAreas);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_DOM_STORAGE_LOCAL_STORAGE_CACHED_AREAS_H_