Persist sessionStorage on disk.

webkit/dom_storage/dom_storage_area.h

Index: webkit/dom_storage/dom_storage_area.h
diff --git a/webkit/dom_storage/dom_storage_area.h b/webkit/dom_storage/dom_storage_area.h
index af43c821a4e206cb20e0670d12db6343a315d64c..be99ba9258d82028cca65be5a731b3b9e5071612 100644
--- a/webkit/dom_storage/dom_storage_area.h
+++ b/webkit/dom_storage/dom_storage_area.h
@@ -9,16 +9,19 @@
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/nullable_string16.h"
 #include "base/string16.h"
 #include "googleurl/src/gurl.h"
-#include "webkit/dom_storage/dom_storage_database.h"
+#include "webkit/dom_storage/dom_storage_database_adapter.h"
 #include "webkit/dom_storage/dom_storage_types.h"
 
 namespace dom_storage {
 
+class DomStorageDatabaseAdapter;
 class DomStorageMap;
 class DomStorageTaskRunner;
+class SessionStorageDatabase;
 
 // Container for a per-origin Map of key/value pairs potentially
 // backed by storage on disk and lazily commits changes to disk.
@@ -31,11 +34,18 @@ class DomStorageArea
   static FilePath DatabaseFileNameFromOrigin(const GURL& origin);
   static GURL OriginFromDatabaseFileName(const FilePath& file_name);
 
+  // Local storage. Backed on disk if directory is nonempty.
   DomStorageArea(int64 namespace_id,
                  const GURL& origin,
                  const FilePath& directory,
                  DomStorageTaskRunner* task_runner);
 
+  // Session storage. Backed on disk if |session_storage_backing| is not NULL.
+  DomStorageArea(int64 namespace_id,
+                 const GURL& origin,
+                 SessionStorageDatabase* session_storage_backing,
+                 DomStorageTaskRunner* task_runner);
+
   const GURL& origin() const { return origin_; }
   int64 namespace_id() const { return namespace_id_; }
 
@@ -108,7 +118,8 @@ class DomStorageArea
   FilePath directory_;
   scoped_refptr<DomStorageTaskRunner> task_runner_;
   scoped_refptr<DomStorageMap> map_;
-  scoped_ptr<DomStorageDatabase> backing_;
+  scoped_ptr<DomStorageDatabaseAdapter> backing_;
+  scoped_refptr<SessionStorageDatabase> session_storage_backing_;
   bool is_initial_import_done_;
   bool is_shutdown_;
   scoped_ptr<CommitBatch> commit_batch_;