Oilpan: Support nested pre-finalizers

Source/platform/heap/ThreadState.cpp

Index: Source/platform/heap/ThreadState.cpp
diff --git a/Source/platform/heap/ThreadState.cpp b/Source/platform/heap/ThreadState.cpp
index 73afe55fb9d405a2dd345e901dbcd85afe6609e6..6b2da6a97f7cf524908d74de251f1014b6ff054c 100644
--- a/Source/platform/heap/ThreadState.cpp
+++ b/Source/platform/heap/ThreadState.cpp
@@ -1296,16 +1296,6 @@ void ThreadState::unlockThreadAttachMutex()
     threadAttachMutex().unlock();
 }
 
-void ThreadState::unregisterPreFinalizerInternal(void* target)
-{
-    checkThread();
-    if (sweepForbidden())
-        return;
-    auto it = m_preFinalizers.find(target);
-    ASSERT(it != m_preFinalizers.end());
-    m_preFinalizers.remove(it);
-}
-
 void ThreadState::invokePreFinalizers()
 {
     checkThread();
@@ -1317,9 +1307,14 @@ void ThreadState::invokePreFinalizers()
 
     SweepForbiddenScope forbiddenScope(this);
     Vector<void*> deadObjects;
-    for (auto& entry : m_preFinalizers) {
-        if (entry.value(entry.key))
-            deadObjects.append(entry.key);
+    for (auto& it : m_preFinalizers) {
+        void* object = it.key;
+        Vector<PreFinalizerCallback>* callbackVector = it.value.get();
+        for (size_t i = 0; i < callbackVector->size(); i++) {
+            if (!(callbackVector->at(i))(object))
+                break;
+            deadObjects.append(object);
+        }
     }
     // FIXME: removeAll is inefficient.  It can shrink repeatedly.
     m_preFinalizers.removeAll(deadObjects);