DOM wrappers that are not retained from Dart should be collected.

Source/WebCore/bindings/dart/DartDOMWrapper.h

Index: Source/WebCore/bindings/dart/DartDOMWrapper.h
diff --git a/Source/WebCore/bindings/dart/DartDOMWrapper.h b/Source/WebCore/bindings/dart/DartDOMWrapper.h
index 3ef436593b0d28a69822cef612c944e3a254f885..d57c8d0dc445ceee3525fb2e413c841d3494cbc6 100644
--- a/Source/WebCore/bindings/dart/DartDOMWrapper.h
+++ b/Source/WebCore/bindings/dart/DartDOMWrapper.h
@@ -31,6 +31,7 @@
 #define DartDOMWrapper_h
 
 #include "DOMStringList.h"
+#include "DartIsolate.h"
 #include "DartUtilities.h"
 #include "EventListener.h"
 #include "EventTarget.h"
@@ -312,8 +313,8 @@ inline void dartListToVector(Dart_Handle list, Vector<Element>& array, Dart_Hand
 
 class DartDOMWrapper {
 public:
-    template <class WebkitClass>
-    static Dart_Handle newWrapper(const char* className, WebkitClass* domObject)
+    template <class WebKitClass>
+    static Dart_Handle newWrapper(const char* className, WebKitClass* domObject)
     {
         Dart_Handle wrapper = instantiateWrapper(className);
         installNativePointers(domObject, wrapper);
@@ -326,8 +327,8 @@ public:
         return toDart(instance, BindingsClass::dartImplementationClassName);
     }
 
-    template <class WebkitClass>
-    static Dart_Handle toDart(WebkitClass* instance, const char* className)
+    template <class WebKitClass>
+    static Dart_Handle toDart(WebKitClass* instance, const char* className)
     {
         if (!instance)
             return 0;
@@ -344,15 +345,15 @@ public:
         return wrapper;
     }
 
-    template <class WebkitClass>
-    static void bindDOMObjectToDartWrapper(WebkitClass* domObject, Dart_Handle wrapper)
+    template <class WebKitClass>
+    static void bindDOMObjectToDartWrapper(WebKitClass* domObject, Dart_Handle wrapper)
     {
         ASSERT(domObject);
         domObject->ref();
         installNativePointers(domObject, wrapper);
 
-        // FIXME: make persistent handle weak and deref domObject in weak callback.
-        Dart_Handle persistentWrapperHandle = Dart_NewPersistentHandle(wrapper);
+        RefPtr<DartIsolate> isolate = DartIsolate::current();
+        Dart_Handle persistentWrapperHandle = isolate->createWeakPersistentHandle(wrapper, domObject, &wrapperWeakCallback<WebKitClass>);
 
         DartDOMMap* domMap = DartUtilities::domMapForCurrentIsolate();
         ASSERT(!domMap->contains(domObject));
@@ -373,14 +374,12 @@ public:
         return reinterpret_cast<typename BindingsClass::NativeType*>(nativePointer);
     }
 
-    static void derefDOMObject(Dart_Handle wrapper, void* domObject);
-
-    template <class WebkitClass>
-    static WebkitClass* receiver(Dart_NativeArguments args)
+    template <class WebKitClass>
+    static WebKitClass* receiver(Dart_NativeArguments args)
     {
         // Type of receiver is ensured by Dart VM runtime, so bypass additional checks.
         void* nativePointer = readNativePointer(Dart_GetNativeArgument(args, 0), kNativeImplementationIndex);
-        WebkitClass* const recv = static_cast<WebkitClass*>(nativePointer);
+        WebKitClass* const recv = static_cast<WebKitClass*>(nativePointer);
         ASSERT(recv); // Never should return 0.
         return recv;
     }
@@ -411,7 +410,6 @@ public:
 private:
     enum NativeFieldIndices {
         kNativeImplementationIndex = 0,
-        kDerefObjectFunctionIndex,
         kNativeFieldCount
     };
 
@@ -436,30 +434,23 @@ private:
         return reinterpret_cast<void*>(value);
     }
 
-    template <class WebkitClass>
-    static void installNativePointers(WebkitClass* domObject, Dart_Handle wrapper)
+    template <class WebKitClass>
+    static void installNativePointers(WebKitClass* domObject, Dart_Handle wrapper)
     {
         ASSERT(domObject);
-        DerefObjectFunction derefObjectFunction = &DartDOMWrapper::derefObject<WebkitClass>;
         writeNativePointer(wrapper, kNativeImplementationIndex, domObject);
-        writeNativePointer(wrapper, kDerefObjectFunctionIndex, reinterpret_cast<void*>(derefObjectFunction));
     }
 
-    typedef void (*DerefObjectFunction)(void*);
-
     template<typename T>
-    static void derefObject(void* pointer)
+    static void wrapperWeakCallback(Dart_Handle, void* domObject)
     {
-        static_cast<T*>(pointer)->deref();
+        DartDOMMap* domMap = DartUtilities::domMapForCurrentIsolate();
+        ASSERT(domMap->contains(domObject));
+        domMap->remove(domObject);
+        static_cast<T*>(domObject)->deref();
     }
 };
 
-template<>
-inline void DartDOMWrapper::derefObject<NPObject>(void*)
-{
-    // FIXME: proper deref.
-}
-
 // ParameterAdapter.
 
 template <typename Value>