Oilpan: improve ScrollableArea handling.

Source/core/page/scrolling/ScrollingCoordinator.h

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 31 matching lines @@
 
 typedef unsigned MainThreadScrollingReasons;
 
 class LocalFrame;
 class FrameView;
 class GraphicsLayer;
 class Page;
 class Region;
 class ScrollableArea;
 
-class CORE_EXPORT ScrollingCoordinator {
+class CORE_EXPORT ScrollingCoordinator final : public NoBaseWillBeGarbageCollectedFinalized<ScrollingCoordinator> {
     WTF_MAKE_NONCOPYABLE(ScrollingCoordinator);
 public:
+    static PassOwnPtrWillBeRawPtr<ScrollingCoordinator> create(Page*);
+
     ~ScrollingCoordinator();
-
-    static PassOwnPtr<ScrollingCoordinator> create(Page*);
+    DECLARE_TRACE();
 
     void willBeDestroyed();
 
     // Return whether this scrolling coordinator handles scrolling for the given frame view.
     bool coordinatesScrollingForFrameView(FrameView*) const;
 
     // Called when any frame has done its layout.
     void notifyLayoutUpdated();
 
     void updateAfterCompositingChangeIfNeeded();
@@ skipping 51 matching lines @@
     // for the results to be valid.
     void reset();
 
 protected:
     explicit ScrollingCoordinator(Page*);
 
     bool isForRootLayer(ScrollableArea*) const;
     bool isForMainFrame(ScrollableArea*) const;
     bool isForViewport(ScrollableArea*) const;
 
-    Page* m_page;
+    RawPtrWillBeMember<Page> m_page;
 
     // Dirty flags used to idenfity what really needs to be computed after compositing is updated.
     bool m_scrollGestureRegionIsDirty;
     bool m_touchEventTargetRectsAreDirty;
     bool m_shouldScrollOnMainThreadDirty;
 
 private:
     bool shouldUpdateAfterCompositingChange() const { return m_scrollGestureRegionIsDirty || m_touchEventTargetRectsAreDirty || m_shouldScrollOnMainThreadDirty || frameViewIsDirty(); }
 
     void setShouldUpdateScrollLayerPositionOnMainThread(MainThreadScrollingReasons);
 
     bool hasVisibleSlowRepaintViewportConstrainedObjects(FrameView*) const;
 
     void setShouldHandleScrollGestureOnMainThreadRegion(const Region&);
     void setTouchEventTargetRects(LayerHitTestRects&);
     void computeTouchEventTargetRects(LayerHitTestRects&);
 
     WebScrollbarLayer* addWebScrollbarLayer(ScrollableArea*, ScrollbarOrientation, PassOwnPtr<WebScrollbarLayer>);
     WebScrollbarLayer* getWebScrollbarLayer(ScrollableArea*, ScrollbarOrientation);
     void removeWebScrollbarLayer(ScrollableArea*, ScrollbarOrientation);
 
     bool frameViewIsDirty() const;
 
-    using ScrollbarMap = HashMap<ScrollableArea*, OwnPtr<WebScrollbarLayer>>;
+    using ScrollbarMap = WillBeHeapHashMap<RawPtrWillBeMember<ScrollableArea>, OwnPtr<WebScrollbarLayer>>;
     ScrollbarMap m_horizontalScrollbars;
     ScrollbarMap m_verticalScrollbars;
     HashSet<const DeprecatedPaintLayer*> m_layersWithTouchRects;
     bool m_wasFrameScrollable;
 
     MainThreadScrollingReasons m_lastMainThreadScrollingReasons;
 };
 
 } // namespace blink
 
 #endif // ScrollingCoordinator_h