Persist sessionStorage on disk.

webkit/dom_storage/dom_storage_context.h

Index: webkit/dom_storage/dom_storage_context.h
diff --git a/webkit/dom_storage/dom_storage_context.h b/webkit/dom_storage/dom_storage_context.h
index c7d57a368b6d1931da0dbf9d3ee220817eff5606..73459acdf38cbb52b2cd171d4406c2eb46b0e012 100644
--- a/webkit/dom_storage/dom_storage_context.h
+++ b/webkit/dom_storage/dom_storage_context.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <map>
+#include <set>
 #include <vector>
 
 #include "base/atomic_sequence_num.h"
@@ -35,6 +36,7 @@ class DomStorageArea;
 class DomStorageNamespace;
 class DomStorageSession;
 class DomStorageTaskRunner;
+class SessionStorageDatabase;
 
 // The Context is the root of an object containment hierachy for
 // Namespaces and Areas related to the owning profile.
@@ -151,10 +153,16 @@ class DomStorageContext
     return session_id_sequence_.GetNext();
   }
 
+  std::string AllocatePersistentSessionId();
+
   // Must be called on the background thread.
-  void CreateSessionNamespace(int64 namespace_id);
+  void CreateSessionNamespace(int64 namespace_id,
+                              const std::string& persistent_namespace_id);
   void DeleteSessionNamespace(int64 namespace_id);
-  void CloneSessionNamespace(int64 existing_id, int64 new_id);
+  void CloneSessionNamespace(int64 existing_id, int64 new_id,
+                             const std::string& new_persistent_id);
+
+  void DoomSessionStorage(const std::string& persistent_namespace_id);
 
  private:
   friend class DomStorageContextTest;
@@ -167,6 +175,8 @@ class DomStorageContext
 
   void ClearSessionOnlyOrigins();
 
+  void DeleteLeftoverDataInCommitSequence();
+
   // Collection of namespaces keyed by id.
   StorageNamespaceMap namespaces_;
 
@@ -191,6 +201,15 @@ class DomStorageContext
   bool is_shutdown_;
   bool force_keep_session_state_;
   scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_;
+  scoped_refptr<SessionStorageDatabase> session_storage_database_;
+
+  // Persistent namespace IDs for sessionStorages which won't be needed for
+  // session restore.
+  std::set<std::string> doomed_persistent_session_ids_;
+
+  // Persistent namespace IDs to protect from leftover data deletion (they will
+  // be needed for session restore).
+  std::set<std::string> protected_persistent_session_ids_;
 };
 
 }  // namespace dom_storage