[poc] curve-filter

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 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 1496 matching lines @@
     } else {
         ScrollbarControlSize scrollbarSize = RegularScrollbar;
         if (actualLayoutObject.styleRef().hasAppearance())
             scrollbarSize = LayoutTheme::theme().scrollbarControlSizeForPart(actualLayoutObject.styleRef().appearance());
         scrollbar = Scrollbar::create(m_scrollableArea.get(), orientation, scrollbarSize, &m_scrollableArea->box().frame()->page()->chromeClient());
         if (orientation == HorizontalScrollbar)
             m_scrollableArea->didAddScrollbar(*scrollbar, HorizontalScrollbar);
         else
             m_scrollableArea->didAddScrollbar(*scrollbar, VerticalScrollbar);
     }
+
     m_scrollableArea->box().document().view()->addChild(scrollbar.get());
+    Page* page = m_scrollableArea->box().frame()->page();
+    scrollbar->setScreenId(Page::screenId(page));
+
     return scrollbar.release();
 }
 
 void PaintLayerScrollableArea::ScrollbarManager::destroyScrollbar(ScrollbarOrientation orientation)
 {
     RefPtrWillBeMember<Scrollbar>& scrollbar = orientation == HorizontalScrollbar ? m_hBar : m_vBar;
     ASSERT(orientation == HorizontalScrollbar ? !m_hBarIsAttached: !m_vBarIsAttached);
     if (!scrollbar)
         return;
 
     m_scrollableArea->setScrollbarNeedsPaintInvalidation(orientation);
 
     if (!scrollbar->isCustomScrollbar())
         m_scrollableArea->willRemoveScrollbar(*scrollbar, orientation);
 
     toFrameView(scrollbar->parent())->removeChild(scrollbar.get());
     scrollbar->disconnectFromScrollableArea();
     scrollbar = nullptr;
 }
 
 DEFINE_TRACE(PaintLayerScrollableArea::ScrollbarManager)
 {
     visitor->trace(m_scrollableArea);
     visitor->trace(m_hBar);
     visitor->trace(m_vBar);
 }
 
 } // namespace blink