[Refactor] Moved scrollbar creation and deletion to ScrollbarManager

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 125 matching lines @@
     // a new one.
    public:
     ScrollbarManager(PaintLayerScrollableArea& scroller)
         : blink::ScrollbarManager(scroller) {}
 
     void SetHasHorizontalScrollbar(bool has_scrollbar) override;
     void SetHasVerticalScrollbar(bool has_scrollbar) override;
 
     void DestroyDetachedScrollbars();
 
-   protected:
-    Scrollbar* CreateScrollbar(ScrollbarOrientation) override;
-    void DestroyScrollbar(ScrollbarOrientation) override;
-
     PaintLayerScrollableArea* ScrollableArea();
   };
 
  public:
   // If a PreventRelayoutScope object is alive, updateAfterLayout() will not
   // re-run box layout as a result of adding or removing scrollbars.
   // Instead, it will mark the PLSA as needing relayout of its box.
   // When the last PreventRelayoutScope object is popped off the stack,
   // box().setNeedsLayout(), and box().scrollbarsChanged() for LayoutBlock's,
   // will be called as appropriate for all marked PLSA's.
@@ skipping 61 matching lines @@
   static PaintLayerScrollableArea* Create(PaintLayer& layer) {
     return new PaintLayerScrollableArea(layer);
   }
 
   ~PaintLayerScrollableArea() override;
   void Dispose();
 
   bool HasHorizontalScrollbar() const { return HorizontalScrollbar(); }
   bool HasVerticalScrollbar() const { return VerticalScrollbar(); }
 
+  void WillRemoveScrollbar(Scrollbar&, ScrollbarOrientation) override;
+
   Scrollbar* HorizontalScrollbar() const override {
     return scrollbar_manager_.HorizontalScrollbar();
   }
   Scrollbar* VerticalScrollbar() const override {
     return scrollbar_manager_.VerticalScrollbar();
   }
 
   PlatformChromeClient* GetChromeClient() const override;
 
   SmoothScrollSequencer* GetSmoothScrollSequencer() const override;
@@ skipping 32 matching lines @@
   IntSize ScrollOffsetInt() const override;
   ScrollOffset GetScrollOffset() const override;
   IntSize MinimumScrollOffsetInt() const override;
   IntSize MaximumScrollOffsetInt() const override;
   IntRect VisibleContentRect(
       IncludeScrollbarsInRect = kExcludeScrollbars) const override;
   int VisibleHeight() const override;
   int VisibleWidth() const override;
   IntSize ContentsSize() const override;
   void ContentsResized() override;
+  LayoutObject* LayoutObjectForScrollbars() const override;
   bool IsScrollable() const override;
   IntPoint LastKnownMousePosition() const override;
   bool ScrollAnimatorEnabled() const override;
   bool ShouldSuspendScrollAnimations() const override;
   bool ScrollbarsCanBeActive() const override;
   void ScrollbarVisibilityChanged() override;
   void ScrollbarFrameRectChanged() override;
   IntRect ScrollableAreaBoundingBox() const override;
   void RegisterForAnimation() override;
   void DeregisterForAnimation() override;
@@ skipping 320 matching lines @@
 
 DEFINE_TYPE_CASTS(PaintLayerScrollableArea,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->IsPaintLayerScrollableArea(),
                   scrollableArea.IsPaintLayerScrollableArea());
 
 }  // namespace blink
 
 #endif  // LayerScrollableArea_h