Initial ResizeObserver implementation

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..e573dd3ea7af7f65c7f8f2b6dad54f6e6ab1be6e
--- /dev/null
+++ b/third_party/WebKit/Source/core/observer/ResizeObserverController.h
@@ -0,0 +1,43 @@
+// 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 : public GarbageCollectedFinalized<ResizeObserverController> {
+
+public:
+
+    static const size_t kRenderLoopLimit = 16;
+
+    ResizeObserverController();
+    virtual ~ResizeObserverController() {};

[szager1, 2016/05/23 19:49:12]

Ditto comment about unnecessary destructors.

[atotic1, 2016/05/25 00:15:54]

Done.

+
+    void addObserver(ResizeObserver&);
+

[szager1, 2016/05/23 19:49:12]

Too many blank lines.

[atotic1, 2016/05/25 00:15:54]

Done.

+    void gatherObservations();
+
+    bool hasObservations();
+
+    void deliverObservations();
+
+    DECLARE_TRACE();
+
+private:
+
+    // Active observers
+    HeapHashSet<Member<ResizeObserver>> m_observers;

[szager1, 2016/05/23 19:49:12]

This should probably be HeapHashSet<WeakMember<ResizeObserver>>.  The document
should not keep the observers alive.

[atotic1, 2016/05/25 00:15:54]

Done.

+};
+
+} // namespace blink
+
+#endif