Restore sessionStorage when chrome restarts.

content/browser/in_process_webkit/dom_storage_context.h

Index: content/browser/in_process_webkit/dom_storage_context.h
diff --git a/content/browser/in_process_webkit/dom_storage_context.h b/content/browser/in_process_webkit/dom_storage_context.h
index 05e404043933470b3198d1cf25b8686e51421ea8..3c7e3b728b26e9ceeb5b8161980b3456b62ffebe 100644
--- a/content/browser/in_process_webkit/dom_storage_context.h
+++ b/content/browser/in_process_webkit/dom_storage_context.h
@@ -67,6 +67,12 @@ class CONTENT_EXPORT DOMStorageContext {
   // namespace if it hasn't been already.
   DOMStorageNamespace* GetStorageNamespace(int64 id, bool allocation_allowed);
 
+  // Creates a session storage namespace which is backed up by the existing
+  // |session_storage_directory|.
+  DOMStorageNamespace* RecreateSessionStorageNamespace(
+      int64 id,
+      const FilePath& session_storage_directory);
+
   // Sometimes an event from one DOM storage message filter requires
   // communication to all of them.
   typedef std::set<DOMStorageMessageFilter*> MessageFilterSet;
@@ -94,6 +100,9 @@ class CONTENT_EXPORT DOMStorageContext {
   // The local storage directory.
   static const FilePath::CharType kLocalStorageDirectory[];
 
+  // The session storage directory.
+  static const FilePath::CharType kSessionStorageDirectory[];
+
   // The local storage file extension.
   static const FilePath::CharType kLocalStorageExtension[];