[Refactor] Moved scrollbar creation and deletion to ScrollbarManager

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

 // Copyright 2015 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 PaintInvalidationCapableScrollableArea_h
 #define PaintInvalidationCapableScrollableArea_h
 
 #include "core/CoreExport.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/scroll/ScrollableArea.h"
@@ skipping 21 matching lines @@
   void InvalidatePaintOfScrollControlsIfNeeded(const PaintInvalidatorContext&);
 
   // Should be called when the previous visual rects are no longer valid.
   void ClearPreviousVisualRects();
 
   virtual IntRect ScrollCornerAndResizerRect() const {
     return ScrollCornerRect();
   }
 
   void DidScrollWithScrollbar(ScrollbarPart, ScrollbarOrientation) override;
+  bool ShouldUseCustomScrollbars(LayoutObject*&) const override;
 
  private:
   virtual LayoutScrollbarPart* ScrollCorner() const = 0;
   virtual LayoutScrollbarPart* Resizer() const = 0;
 
   void ScrollControlWasSetNeedsPaintInvalidation() override;
 
   void SetHorizontalScrollbarVisualRect(const LayoutRect&);
   void SetVerticalScrollbarVisualRect(const LayoutRect&);
   void SetScrollCornerAndResizerVisualRect(const LayoutRect&);
 
   bool horizontal_scrollbar_previously_was_overlay_;
   bool vertical_scrollbar_previously_was_overlay_;
   LayoutRect horizontal_scrollbar_visual_rect_;
   LayoutRect vertical_scrollbar_visual_rect_;
   LayoutRect scroll_corner_and_resizer_visual_rect_;
 };
 
 }  // namespace blink
 
 #endif  // PaintInvalidationCapableScrollableArea_h