Revert of Make GraphicsLayer the DisplayItemClient for scrollbars composited via PaintLayerCompositor.

third_party/WebKit/Source/platform/graphics/paint/DisplayItem.cpp

 // Copyright 2014 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.
 
 #include "platform/graphics/paint/DisplayItem.h"
 
 namespace blink {
 
 struct SameSizeAsDisplayItem {
     virtual ~SameSizeAsDisplayItem() { } // Allocate vtable pointer.
@@ skipping 83 matching lines @@
         DEBUG_STRING_CASE(ScrollbarBackButtonStart);
         DEBUG_STRING_CASE(ScrollbarBackground);
         DEBUG_STRING_CASE(ScrollbarBackTrack);
         DEBUG_STRING_CASE(ScrollbarCorner);
         DEBUG_STRING_CASE(ScrollbarForwardButtonEnd);
         DEBUG_STRING_CASE(ScrollbarForwardButtonStart);
         DEBUG_STRING_CASE(ScrollbarForwardTrack);
         DEBUG_STRING_CASE(ScrollbarThumb);
         DEBUG_STRING_CASE(ScrollbarTickmarks);
         DEBUG_STRING_CASE(ScrollbarTrackBackground);
-        DEBUG_STRING_CASE(ScrollbarCompositedScrollbar);
         DEBUG_STRING_CASE(SelectionTint);
         DEBUG_STRING_CASE(TableCellBackgroundFromColumnGroup);
         DEBUG_STRING_CASE(TableCellBackgroundFromColumn);
         DEBUG_STRING_CASE(TableCellBackgroundFromSection);
         DEBUG_STRING_CASE(TableCellBackgroundFromRow);
         DEBUG_STRING_CASE(VideoBitmap);
         DEBUG_STRING_CASE(WebPlugin);
         DEBUG_STRING_CASE(WebFont);
 
         DEFAULT_CASE;
@@ skipping 134 matching lines @@
     stringBuilder.append('"');
     if (m_skippedCache)
         stringBuilder.append(", skippedCache: true");
     if (m_scope)
         stringBuilder.append(String::format(", scope: %d", m_scope));
 }
 
 #endif
 
 } // namespace blink