ResizeObserver implementation, part 2: lifetime

third_party/WebKit/Source/core/observer/ResizeObservation.h

Index: third_party/WebKit/Source/core/observer/ResizeObservation.h
diff --git a/third_party/WebKit/Source/core/observer/ResizeObservation.h b/third_party/WebKit/Source/core/observer/ResizeObservation.h
new file mode 100644
index 0000000000000000000000000000000000000000..68d45d5120bc851e99d5cb2d96cf8231af967834
--- /dev/null
+++ b/third_party/WebKit/Source/core/observer/ResizeObservation.h
@@ -0,0 +1,35 @@
+// 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 ResizeObservation_h
+#define ResizeObservation_h
+
+#include "core/observer/ResizeObserverEntry.h"
+#include "platform/geometry/LayoutSize.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class Element;
+class ResizeObserver;
+
+// ResizeObservation represents an element that is being observed.
+class ResizeObservation : public GarbageCollected<ResizeObservation> {

[esprehn, 2016/07/21 17:52:28]

final

[atotic1, 2016/07/21 19:15:00]

Done.

+public:
+    ResizeObservation(Element* target, ResizeObserver*);
+
+    Element* target() const { return m_target; }
+
+    DECLARE_TRACE();
+
+private:
+    WeakMember<Element> m_target;
+    // m_observer only purpose is to maintain a strong reference
+    // to the ResizeObserver, to prevent it from being garbage-collected.

[esprehn, 2016/07/21 17:52:28]

is this still true once you go to a push model?

[atotic1, 2016/07/21 19:15:00]

Good catch, no it is not. Done.

+    Member<ResizeObserver> m_observer;
+};
+
+} // namespace blink
+
+#endif // ResizeObservation_h