Persist sessionStorage on disk.

content/browser/dom_storage/dom_storage_context_impl.h

Index: content/browser/dom_storage/dom_storage_context_impl.h
diff --git a/content/browser/dom_storage/dom_storage_context_impl.h b/content/browser/dom_storage/dom_storage_context_impl.h
index 9256877852e9792a955ff3772030db0af5e44eba..5959ce880eb925aaefec1580c2f6fb2149fe3819 100644
--- a/content/browser/dom_storage/dom_storage_context_impl.h
+++ b/content/browser/dom_storage/dom_storage_context_impl.h
@@ -13,6 +13,10 @@
 #include "content/public/browser/dom_storage_context.h"
 #include "webkit/dom_storage/dom_storage_types.h"
 
+namespace content {
+class SessionStorageNamespace;
+}
+
 namespace dom_storage {
 class DomStorageContext;
 }
@@ -41,6 +45,10 @@ class CONTENT_EXPORT DOMStorageContextImpl :
   virtual FilePath GetFilePath(const string16& origin_id) const OVERRIDE;
   virtual void DeleteForOrigin(const string16& origin_id) OVERRIDE;
   virtual void DeleteLocalStorageFile(const FilePath& file_path) OVERRIDE;
+  virtual void DoomSessionStorage(
+      const std::string& persistent_namespace_id) OVERRIDE;
+  virtual scoped_refptr<content::SessionStorageNamespace>
+      RecreateSessionStorage(const std::string& persistent_id) OVERRIDE;
 
   // Called to free up memory that's not strictly needed.
   void PurgeMemory();