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

Source/WebCore/bindings/dart/DartUtilities.cpp

 // Copyright 2011, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * Redistributions in binary form must reproduce the above
@@ skipping 244 matching lines @@
 
 static DartDOMData* domDataForIsolate(Dart_Isolate isolate)
 {
     IsolateToDartDOMDataMap::iterator it = isolateToDartDOMDataMap().find(isolate);
     ASSERT(it != isolateToDartDOMDataMap().end());
     return it->second;
 }
 
 static DartDOMData* currentDOMData()
 {
-    return domDataForIsolate(DartIsolate::current()->isolate());
+    return domDataForIsolate(Dart_CurrentIsolate());
 }
 
 void DartUtilities::registerDOMIsolate(Dart_Isolate isolate, PassRefPtr<DartApplicationLoader> applicationLoader, ScriptExecutionContext* context)
 {
     ASSERT(!isolateToDartDOMDataMap().contains(isolate));
     isolateToDartDOMDataMap().set(isolate, new DartDOMData(applicationLoader, context));
     ASSERT(context->isDocument());
 }
 
 void DartUtilities::registerPureIsolate(Dart_Isolate isolate, PassRefPtr<DartApplicationLoader> applicationLoader)
@@ skipping 99 matching lines @@
 }
 
 PassRefPtr<ScriptCallStack> DartUtilities::createScriptCallStack()
 {
     // FIXME: wrap current dart call stack as ScriptCallStack.
     Vector<ScriptCallFrame> wrappedCallFrames;
     wrappedCallFrames.append(ScriptCallFrame("undefined", "undefined", 0));
     return ScriptCallStack::create(wrappedCallFrames);
 }
 
+class DartWeakCallback
+{
+public:
+    DartWeakCallback(void* peer, Dart_WeakPersistentHandleFinalizer weakCallback)
+        : peer(peer)
+        , weakCallback(weakCallback)
+        , object(0)
+    {
+    }
+
+    void* peer;

[Anton Muhin, 2012/03/30 11:36:00]

nit: m_peer, m_weakCallback, etc.?

+    Dart_WeakPersistentHandleFinalizer weakCallback;
+    Dart_Handle object;
+};
+
+static void weakCallbackWrapper(Dart_Handle object, void* peer)
+{
+    DartWeakCallback* callback = static_cast<DartWeakCallback*>(peer);
+    DartUtilities::domDataForCurrentIsolate()->weakCallbacks()->remove(callback);
+    (*callback->weakCallback)(object, callback->peer);
+    delete callback;
+}
+
+Dart_Handle DartUtilities::createWeakPersistentHandle(Dart_Handle object, void* peer, Dart_WeakPersistentHandleFinalizer weakCallback)
+{
+    DartWeakCallback* callback = new DartWeakCallback(peer, weakCallback);
+    callback->object = Dart_NewWeakPersistentHandle(object, callback, &weakCallbackWrapper);
+    domDataForCurrentIsolate()->weakCallbacks()->add(callback);
+    return callback->object;
+}
+
+void DartUtilities::disposeWeakPersistentHandles()
+{
+    DartWeakCallbacks* weakCallbacks = domDataForCurrentIsolate()->weakCallbacks();
+    for (DartWeakCallbacks::iterator it = weakCallbacks->begin(); it != weakCallbacks->end(); ++it) {
+        DartWeakCallback* callback = *it;
+        (*callback->weakCallback)(callback->object, callback->peer);
+        delete callback;
+    }
+    weakCallbacks->clear();
+}
+
 const uint8_t* DartUtilities::fullSnapshot()
 {
     static const uint8_t snapshotBuffer[] = {
 // DartSnapshot.bytes is generated by build system.
 #include "DartSnapshot.bytes"
     };
     return snapshotBuffer;
 }
 
 void DartUtilities::reportProblem(ScriptExecutionContext* context, Dart_Handle result)
@@ skipping 48 matching lines @@
     ASSERT(!Dart_IsError(library));
     Dart_Handle args[2] = {0};
     args[0] = Dart_NewString(fileName);
     args[1] = Dart_NewInteger(lineNumber);
     Dart_Handle result = Dart_InvokeStatic(library, Dart_NewString("Utils"), Dart_NewString("makeNotImplementedException"), 2, args);
     ASSERT(!Dart_IsError(result));
     return result;
 }
 
 }