Oilpan: fix tracing of un-initialized part objects during conservative GCs.

Source/platform/heap/HeapTest.cpp

 /*
  * Copyright (C) 2013 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 246 matching lines @@
         ASSERT(header->payload());
         m_count++;
     }
 
     virtual void mark(FinalizedHeapObjectHeader* header, TraceCallback callback) OVERRIDE
     {
         ASSERT(header->payload());
         m_count++;
     }
 
-    virtual void markConservatively(HeapObjectHeader* header) OVERRIDE
-    {
-        ASSERT_NOT_REACHED();
-    }
-
-    virtual void markConservatively(FinalizedHeapObjectHeader* header) OVERRIDE
-    {
-        ASSERT_NOT_REACHED();
-    }
-
     virtual void registerWeakMembers(const void*, const void*, WeakPointerCallback) OVERRIDE { }
     virtual void registerWeakTable(const void*, EphemeronCallback, EphemeronCallback) OVERRIDE { }
 #if ENABLE(ASSERT)
     virtual bool weakTableRegistered(const void*) OVERRIDE { return false; }
 #endif
     virtual void registerWeakCell(void**, WeakPointerCallback) OVERRIDE { }
     virtual bool isMarked(const void*) OVERRIDE { return false; }
 
     FOR_EACH_TYPED_HEAP(DEFINE_VISITOR_METHODS)
 
@@ skipping 4555 matching lines @@
     static volatile uintptr_t s_workerObjectPointer;
 };
 
 volatile uintptr_t DeadBitTester::s_workerObjectPointer = 0;
 
 TEST(HeapTest, ObjectDeadBit)
 {
     DeadBitTester::test();
 }
 
+static bool allocateAndReturnBool()
+{
+    Heap::collectGarbage(ThreadState::HeapPointersOnStack);
+    return true;
+}
+
 class MixinWithGarbageCollectionInConstructor : public GarbageCollectedMixin {
 public:
-    MixinWithGarbageCollectionInConstructor()
+    MixinWithGarbageCollectionInConstructor() : m_dummy(allocateAndReturnBool())
     {
-        Heap::collectGarbage(ThreadState::HeapPointersOnStack);
     }
+private:
+    bool m_dummy;
 };
 
 class ClassWithGarbageCollectingMixinConstructor
     : public GarbageCollected<ClassWithGarbageCollectingMixinConstructor>
     , public MixinWithGarbageCollectionInConstructor {
     USING_GARBAGE_COLLECTED_MIXIN(ClassWithGarbageCollectingMixinConstructor);
 public:
     ClassWithGarbageCollectingMixinConstructor() : m_wrapper(IntWrapper::create(32))
     {
     }
@@ skipping 174 matching lines @@
 
     {
         TraceIfNeededTester<HeapVector<Member<SimpleObject> > >* m_vec = TraceIfNeededTester<HeapVector<Member<SimpleObject> > >::create();
         m_vec->obj().append(SimpleObject::create());
         visitor.reset();
         m_vec->trace(&visitor);
         EXPECT_EQ(2u, visitor.count());
     }
 }
 
+class PartObjectWithVirtualMethod {
+public:
+    virtual void trace(Visitor*) { }
+};
+
+class ObjectWithVirtualPartObject : public GarbageCollected<ObjectWithVirtualPartObject> {
+public:
+    ObjectWithVirtualPartObject() : m_dummy(allocateAndReturnBool()) { }
+    void trace(Visitor* visitor) { visitor->trace(m_part); }
+private:
+    bool m_dummy;
+    PartObjectWithVirtualMethod m_part;
+};
+
+TEST(HeapTest, PartObjectWithVirtualMethod)
+{
+    ObjectWithVirtualPartObject* object = new ObjectWithVirtualPartObject();
+    EXPECT_TRUE(object);
+}
+
 } // namespace blink