Add virtual destructors to IntersectionObserverCallback

third_party/WebKit/Source/core/dom/IntersectionObservation.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef IntersectionObservation_h
 #define IntersectionObservation_h
 
 #include "platform/geometry/LayoutRect.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Element;
 class IntersectionObserver;
 class Node;
 
 class IntersectionObservation : public GarbageCollectedFinalized<IntersectionObservation> {
 public:
     IntersectionObservation(IntersectionObserver&, Element&, bool shouldReportRootBounds);
+    virtual ~IntersectionObservation();

[dcheng, 2016/01/14 07:06:09]

No virtual needed here and on IntersectionObserver: if you're worried someone
will subclass it, you can mark these two classes final instead.

[sof, 2016/01/14 07:13:09]

Adding a TODO above this class decl, like

 TODO(Oilpan): switch to GarbageCollected<> when removing transition types.

would be worth doing, so that we don't forget.

[haraken, 2016/01/14 07:23:44]

Yeah, makes sense. We considered to introduce
GarbageCollectedFinalizedWillBeGarbageCollected before but rejected the idea
because it's a bit too crazy :)

[szager1, 2016/01/14 07:24:37]

Done.

[szager1, 2016/01/14 07:24:37]

Done.

 
     struct IntersectionGeometry {
         LayoutRect targetRect;
         LayoutRect intersectionRect;
         LayoutRect rootRect;
     };
 
     IntersectionObserver& observer() const { return *m_observer; }
     Element* target() const;
     bool isActive() const { return m_active; }
@@ skipping 21 matching lines @@
     WeakPtrWillBeWeakMember<Node> m_target;
 
     unsigned m_active : 1;
     unsigned m_shouldReportRootBounds : 1;
     unsigned m_lastThresholdIndex : 30;
 };
 
 } // namespace blink
 
 #endif // IntersectionObservation_h