Oilpan: improve ScrollableArea handling.

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 54 matching lines @@
 class LayoutView;
 class Page;
 class ScrollingCoordinator;
 class TracedValue;
 struct AnnotatedRegionValue;
 struct CompositedSelection;
 
 typedef unsigned long long DOMTimeStamp;
 
 class CORE_EXPORT FrameView final : public Widget, public ScrollableArea {
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(FrameView);
 public:
     friend class LayoutView;
     friend class Internals;
 
     static PassRefPtrWillBeRawPtr<FrameView> create(LocalFrame*);
     static PassRefPtrWillBeRawPtr<FrameView> create(LocalFrame*, const IntSize& initialSize);
 
     virtual ~FrameView();
 
     virtual void invalidateRect(const IntRect&) override;
@@ skipping 196 matching lines @@
     virtual void scrollbarStyleChanged() override;
 
     LayoutBox* embeddedContentBox() const;
 
     void setTracksPaintInvalidations(bool);
     bool isTrackingPaintInvalidations() const { return m_isTrackingPaintInvalidations; }
     void resetTrackedPaintInvalidations();
 
     String trackedPaintInvalidationRectsAsText() const;
 
-    typedef HashSet<ScrollableArea*> ScrollableAreaSet;
+    using ScrollableAreaSet = WillBeHeapHashSet<RawPtrWillBeMember<ScrollableArea>>;
     void addScrollableArea(ScrollableArea*);
     void removeScrollableArea(ScrollableArea*);
     const ScrollableAreaSet* scrollableAreas() const { return m_scrollableAreas.get(); }
 
     void addAnimatingScrollableArea(ScrollableArea*);
     void removeAnimatingScrollableArea(ScrollableArea*);
     const ScrollableAreaSet* animatingScrollableAreas() const { return m_animatingScrollableAreas.get(); }
 
     // With CSS style "resize:" enabled, a little resizer handle will appear at the bottom
     // right of the object. We keep track of these resizer areas for checking if touches
@@ skipping 477 matching lines @@
     unsigned m_visuallyNonEmptyCharacterCount;
     unsigned m_visuallyNonEmptyPixelCount;
     bool m_isVisuallyNonEmpty;
     bool m_firstVisuallyNonEmptyLayoutCallbackPending;
 
     RefPtrWillBeMember<Node> m_maintainScrollPositionAnchor;
 
     // layoutObject to hold our custom scroll corner.
     LayoutScrollbarPart* m_scrollCorner;
 
-    OwnPtr<ScrollableAreaSet> m_scrollableAreas;
-    OwnPtr<ScrollableAreaSet> m_animatingScrollableAreas;
+    OwnPtrWillBeMember<ScrollableAreaSet> m_scrollableAreas;
+    OwnPtrWillBeMember<ScrollableAreaSet> m_animatingScrollableAreas;
     OwnPtr<ResizerAreaSet> m_resizerAreas;
     OwnPtr<ViewportConstrainedObjectSet> m_viewportConstrainedObjects;
     OwnPtrWillBeMember<FrameViewAutoSizeInfo> m_autoSizeInfo;
 
     IntSize m_inputEventsOffsetForEmulation;
     float m_inputEventsScaleFactorForEmulation;
 
     IntSize m_layoutSize;
     bool m_layoutSizeFixedToFrameSize;
 
@@ skipping 35 matching lines @@
     IntPoint m_panScrollIconPoint;
     bool m_shouldDrawPanScrollIcon;
 
     bool m_clipsRepaints;
 
     OwnPtr<LayoutAnalyzer> m_analyzer;
 
     // Exists only on root frame.
     // TODO(bokan): crbug.com/484188. We should specialize FrameView for the
     // main frame.
-    OwnPtr<ScrollableArea> m_viewportScrollableArea;
+    OwnPtrWillBeMember<ScrollableArea> m_viewportScrollableArea;
 };
 
 inline void FrameView::incrementVisuallyNonEmptyCharacterCount(unsigned count)
 {
     if (m_isVisuallyNonEmpty)
         return;
     m_visuallyNonEmptyCharacterCount += count;
     // Use a threshold value to prevent very small amounts of visible content from triggering didFirstVisuallyNonEmptyLayout.
     // The first few hundred characters rarely contain the interesting content of the page.
     static const unsigned visualCharacterThreshold = 200;
@@ skipping 10 matching lines @@
     static const unsigned visualPixelThreshold = 32 * 32;
     if (m_visuallyNonEmptyPixelCount > visualPixelThreshold)
         setIsVisuallyNonEmpty();
 }
 
 DEFINE_TYPE_CASTS(FrameView, Widget, widget, widget->isFrameView(), widget.isFrameView());
 
 } // namespace blink
 
 #endif // FrameView_h