IntersectionObserver: second cut.

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

+// Copyright 2015 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 IntersectionObserverController_h
+#define IntersectionObserverController_h
+
+#include "core/dom/Element.h"
+#include "core/dom/IntersectionObserver.h"
+#include "platform/Timer.h"
+#include "platform/heap/Handle.h"
+#include "wtf/HashSet.h"
+#include "wtf/RefCounted.h"
+
+namespace blink {
+
+class Document;
+template<typename T> class Timer;
+
+class IntersectionObserverController : public GarbageCollectedFinalized<IntersectionObserverController> {
+public:
+    IntersectionObserverController();

[esprehn, 2015/12/17 01:40:29]

also destructor, and put it in the .cpp file

[szager1, 2015/12/17 20:27:26]

Done.

+
+    void scheduleIntersectionObserverForDelivery(IntersectionObserver&);
+    void resumeSuspendedIntersectionObservers();
+    void deliverIntersectionObservations(Timer<IntersectionObserverController>*);
+    void computeTrackedIntersectionObservations();
+    void addTrackedObserver(IntersectionObserver&);
+    void removeTrackedObserversForRoot(Element&);
+    void dispose();
+
+    DECLARE_TRACE();
+
+private:
+    Timer<IntersectionObserverController> m_timer;
+    // IntersectionObservers for which this is the tracking document.
+    HeapHashSet<WeakMember<IntersectionObserver>> m_trackedIntersectionObservers;
+    // IntersectionObservers for which this is the execution context of the callback.
+    HeapHashSet<Member<IntersectionObserver>> m_activeIntersectionObservers;
+    HeapHashSet<Member<IntersectionObserver>> m_suspendedIntersectionObservers;
+};
+
+} // namespace blink
+
+#endif // IntersectionObservationRegistry_h