ResizeObserver implementation, part 2: lifetime

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

Index: third_party/WebKit/Source/core/observer/ResizeObserverController.h
diff --git a/third_party/WebKit/Source/core/observer/ResizeObserverController.h b/third_party/WebKit/Source/core/observer/ResizeObserverController.h
new file mode 100644
index 0000000000000000000000000000000000000000..e84ef621ee747c31a93d6245c504355aaccd05e0
--- /dev/null
+++ b/third_party/WebKit/Source/core/observer/ResizeObserverController.h
@@ -0,0 +1,31 @@
+// 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 ResizeObserverController_h
+#define ResizeObserverController_h
+
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class ResizeObserver;
+
+// ResizeObserverController keeps track of all ResizeObservers
+// in a single Document.
+class ResizeObserverController final : public GarbageCollected<ResizeObserverController> {
+public:
+    ResizeObserverController();
+
+    void addObserver(ResizeObserver&);
+
+    DECLARE_TRACE();
+
+private:
+    // Active observers
+    HeapHashSet<WeakMember<ResizeObserver>> m_observers;
+};
+
+} // namespace blink
+
+#endif