Oilpan: IDBCursor should be detached from IDBRequest when the IDBRequest stops

Source/platform/LifecycleNotifier.h

Index: Source/platform/LifecycleNotifier.h
diff --git a/Source/platform/LifecycleNotifier.h b/Source/platform/LifecycleNotifier.h
index 57d684f009aa4b463b3ac7e83c32ac36dabbf581..3d64a697382b3e4436bafdfbdf42cb5e53155f6d 100644
--- a/Source/platform/LifecycleNotifier.h
+++ b/Source/platform/LifecycleNotifier.h
@@ -47,14 +47,13 @@ public:
         return adoptPtr(new LifecycleNotifier(context));
     }
 
-
     virtual ~LifecycleNotifier();
 
-
     // FIXME: this won't need to be virtual anymore.
     virtual void addObserver(Observer*);
     virtual void removeObserver(Observer*);
 
+    void notifyContextWillBeDestroyed();
     bool isIteratingOverObservers() const { return m_iterating != IteratingNone; }
 
 protected:
@@ -98,6 +97,17 @@ inline LifecycleNotifier<T>::~LifecycleNotifier()
 }
 
 template<typename T>
+inline void LifecycleNotifier<T>::notifyContextWillBeDestroyed()
+{
+    TemporaryChange<IterationType> scope(this->m_iterating, IteratingOverAll);
+    for (typename ObserverSet::iterator it = m_observers.begin(); it != m_observers.end(); it = m_observers.begin()) {
+        Observer* observer = *it;
+        ASSERT(observer->lifecycleContext() == m_context);
+        observer->contextWillBeDestroyed();
+    }
+}
+
+template<typename T>
 inline void LifecycleNotifier<T>::addObserver(typename LifecycleNotifier<T>::Observer* observer)
 {
     RELEASE_ASSERT(m_iterating != IteratingOverAll);