Oilpan: introduce eager finalization.

Source/core/events/EventTarget.h

Index: Source/core/events/EventTarget.h
diff --git a/Source/core/events/EventTarget.h b/Source/core/events/EventTarget.h
index 1b33c2c444d5a8d52f2c334b82b2f1a5210c7f85..8af426ddb8137784491b45e684d2cc49232344b3 100644
--- a/Source/core/events/EventTarget.h
+++ b/Source/core/events/EventTarget.h
@@ -196,7 +196,18 @@ private:
 // #if-switch here, in order to avoid a lot of "#if ENABLE(OILPAN)"-s sprinkled in the derived classes.
 #if ENABLE(OILPAN)
 template <typename T>
-class RefCountedGarbageCollectedEventTargetWithInlineData : public EventTargetWithInlineData { };
+class RefCountedGarbageCollectedEventTargetWithInlineData : public EventTargetWithInlineData {
+public:
+    GC_PLUGIN_IGNORE("491488")
+    void* operator new(size_t size)

[haraken, 2015/06/01 08:42:52]

I'm OK with this approach, but it's error-prone that we sometimes have to
override 'new' to allocate objects on the eager sweep heap as intended. We
should have a verification system for this.

- One way to do this would be to use a GC plugin, as you suggested.

- Another way would be to do the verification at runtime, like this:

#define EAGERLY_FINALIZE() \
  EagerlySweptDestructor m_destructor;

class EagerlySweptDestructor {
  ~EagerlySweptDestructor() {
    ASSERT(isSweepingEagerHeap());
  }
};

- Having both verifications sounds much better :)

[haraken, 2015/06/01 09:12:58]

You can implement the verirication(s) in a follow-up even if you want.

[sof, 2015/06/01 14:51:36]

Will followup, at least for the latter one.

+    {
+        // If T is eagerly finalized, it needs to be allocated accordingly.
+        // Redefinition of the operator is needed to accomplish that, as otherwise
+        // it would be allocated using GarbageCollected<EventTarget>'s operator new.
+        // EventTarget is not eagerly finalized.
+        return allocateObject(size, IsEagerlyFinalizedType<T>::value);
+    }
+};
 #else
 template <typename T>
 class RefCountedGarbageCollectedEventTargetWithInlineData : public RefCountedGarbageCollected<T>, public EventTargetWithInlineData {