Persist sessionStorage on disk.

webkit/dom_storage/session_storage_database.h

Index: webkit/dom_storage/session_storage_database.h
diff --git a/webkit/dom_storage/session_storage_database.h b/webkit/dom_storage/session_storage_database.h
index 5b427fd8510a8b97f055d66c32965389eb482485..70409265d9e54b92cf6c9ac011590a85bd13fcdc 100644
--- a/webkit/dom_storage/session_storage_database.h
+++ b/webkit/dom_storage/session_storage_database.h
@@ -54,14 +54,17 @@ class SessionStorageDatabase :
 
   // Creates shallow copies of the areas for |namespace_id| and associates them
   // with |new_namespace_id|.
-  bool CloneNamespace(int64 namespace_id, int64 new_namespace_id);
+  void CloneNamespace(int64 namespace_id, int64 new_namespace_id);
 
   // Deletes the data for |namespace_id| and |origin|.
-  bool DeleteArea(int64 namespace_id, const GURL& origin);
+  void DeleteArea(int64 namespace_id, const GURL& origin);
 
   // Deletes the data for |namespace_id|.
   bool DeleteNamespace(int64 namespace_id);
 
+  // Reads all namespace ids from the database.
+  bool ReadNamespaceIds(std::vector<int64>* namespace_ids);
+
  private:
   friend class base::RefCountedThreadSafe<SessionStorageDatabase>;
   friend class SessionStorageDatabaseTest;
@@ -108,12 +111,12 @@ class SessionStorageDatabase :
                           leveldb::WriteBatch* batch);
 
   // Helpers for deleting data for |namespace_id| and |origin|.
-  bool DeleteArea(int64 namespace_id,
-                  const std::string& origin,
-                  leveldb::WriteBatch* batch);
-  bool DeleteArea(const std::string& namespace_id_str,
-                  const std::string& origin,
-                  leveldb::WriteBatch* batch);
+  bool DeleteAreaHelper(int64 namespace_id,
+                        const std::string& origin,
+                        leveldb::WriteBatch* batch);
+  bool DeleteAreaHelper(const std::string& namespace_id_str,
+                        const std::string& origin,
+                        leveldb::WriteBatch* batch);
 
   // Retrieves the map id for |namespace_id| and |origin|. It's not an error if
   // the map doesn't exist.