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 ca2b570f618d74cb9cc0f66e3717faf6fde6fb4a..f54d65adfadb31e941e4033b0dd57caba57c9a85 100644
--- a/webkit/dom_storage/dom_storage_context.h
+++ b/webkit/dom_storage/dom_storage_context.h
@@ -35,6 +35,7 @@ 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.
@@ -88,6 +89,13 @@ class DomStorageContext
     virtual ~EventObserver() {}
   };
 
+  class SessionStorageObserver {
+   public:
+    virtual void OnSessionStorageNamespaceAssociated(
+        int64 real_namespace_id) = 0;
+    virtual ~SessionStorageObserver() {}
+  };
+
   DomStorageContext(
       const FilePath& localstorage_directory,  // empty for incognito profiles
       const FilePath& sessionstorage_directory,  // empty for incognito profiles
@@ -148,6 +156,15 @@ class DomStorageContext
       const DomStorageArea* area,
       const GURL& page_url);
 
+  // Adds |observer| to get notified about the association between
+  // |namespace_id| and its real id in the database.
+  void AddSessionStorageObserver(int64 namespace_id,
+                                 SessionStorageObserver* observer);
+  void RemoveSessionStorageObserver(int64 namespace_id);
+
+  void NotifySessionStorageNamespaceAssociated(int64 namespace_id,
+                                               int64 real_namespace_id);
+
   // May be called on any thread.
   int64 AllocateSessionId() {
     return session_id_sequence_.GetNext();
@@ -158,6 +175,9 @@ class DomStorageContext
   void DeleteSessionNamespace(int64 namespace_id);
   void CloneSessionNamespace(int64 existing_id, int64 new_id);
 
+  // May be called on any thread.
+  void AssociateSessionStorage(int64 namespace_id, int64 real_id);
+
  private:
   friend class DomStorageContextTest;
   FRIEND_TEST_ALL_PREFIXES(DomStorageContextTest, Basics);
@@ -169,6 +189,11 @@ class DomStorageContext
 
   void ClearLocalStateInCommitSequence();
 
+  void DeleteSessionNamespaceInCommitSequence(int64 namespace_id);
+  void DeleteLeftoverDataInCommitSequence();
+
+  void SessionStorageAssociated(int64 id, int64 real_id);
+
   // Collection of namespaces keyed by id.
   StorageNamespaceMap namespaces_;
 
@@ -186,6 +211,10 @@ class DomStorageContext
   // List of objects observing local storage events.
   ObserverList<EventObserver> event_observers_;
 
+  // Map of objects observing the association between session storage namespace
+  // ids and real ids in the database.
+  std::map<int64, SessionStorageObserver*> session_storage_observers_;
+
   // We use a 32 bit identifier for per tab storage sessions.
   // At a tab per second, this range is large enough for 68 years.
   base::AtomicSequenceNumber session_id_sequence_;
@@ -194,6 +223,7 @@ class DomStorageContext
   bool clear_local_state_;
   bool save_session_state_;
   scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_;
+  scoped_refptr<SessionStorageDatabase> session_storage_database_;
 };
 
 }  // namespace dom_storage