Initial ResizeObserver implementation

third_party/WebKit/Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
@@ skipping 754 matching lines @@
 
     void collectAnnotatedRegions(LayoutObject&, Vector<AnnotatedRegionValue>&) const;
 
     template <typename Function> void forAllNonThrottledFrameViews(const Function&);
 
     void setNeedsUpdateViewportIntersection();
     void updateViewportIntersectionsForSubtree(LifeCycleUpdateOption);
     void updateViewportIntersectionIfNeeded();
     void notifyRenderThrottlingObservers();
     void updateThrottlingStatus();
+    void notifyResizeObserver();
 
     // PaintInvalidationCapableScrollableArea
     LayoutBox& boxForScrollControlPaintInvalidation() const override;
     LayoutScrollbarPart* resizer() const override { return nullptr; }
 
     LayoutSize m_size;
 
     typedef HashSet<RefPtr<LayoutEmbeddedObject>> EmbeddedObjectSet;
     EmbeddedObjectSet m_partUpdateSet;
 
@@ skipping 166 matching lines @@
     if (m_visuallyNonEmptyPixelCount > visualPixelThreshold)
         setIsVisuallyNonEmpty();
 }
 
 DEFINE_TYPE_CASTS(FrameView, Widget, widget, widget->isFrameView(), widget.isFrameView());
 DEFINE_TYPE_CASTS(FrameView, ScrollableArea, scrollableArea, scrollableArea->isFrameView(), scrollableArea.isFrameView());
 
 } // namespace blink
 
 #endif // FrameView_h