Reland of place pinch scrollbars with regular scrollbars.

Source/core/paint/DeprecatedPaintLayerScrollableArea.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 31 matching lines @@
  */
 
 #include "config.h"
 #include "core/paint/DeprecatedPaintLayerScrollableArea.h"
 
 #include "core/css/PseudoStyleRequest.h"
 #include "core/dom/AXObjectCache.h"
 #include "core/dom/Node.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/FrameSelection.h"
+#include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutGeometryMap.h"
 #include "core/layout/LayoutPart.h"
 #include "core/layout/LayoutScrollbar.h"
 #include "core/layout/LayoutScrollbarPart.h"
 #include "core/layout/LayoutTheme.h"
@@ skipping 101 matching lines @@
     ScrollableArea::trace(visitor);
 }
 
 HostWindow* DeprecatedPaintLayerScrollableArea::hostWindow() const
 {
     if (Page* page = box().frame()->page())
         return &page->chromeClient();
     return nullptr;
 }
 
+GraphicsLayer* DeprecatedPaintLayerScrollableArea::layerForScrollbarContainer() const
+{
+    if (layer()->isRootLayer())
+        return box().frame()->host()->visualViewport().layerForScrollbarContainer();
+    return layerForContainer();
+}
+
 GraphicsLayer* DeprecatedPaintLayerScrollableArea::layerForScrolling() const
 {
     return layer()->hasCompositedDeprecatedPaintLayerMapping() ? layer()->compositedDeprecatedPaintLayerMapping()->scrollingContentsLayer() : 0;
 }
 
 GraphicsLayer* DeprecatedPaintLayerScrollableArea::layerForHorizontalScrollbar() const
 {
     // See crbug.com/343132.
     DisableCompositingQueryAsserts disabler;
 
@@ skipping 1288 matching lines @@
         return false;
 
     LocalFrame* frame = box().frame();
     if (!frame || !frame->isMainFrame() || !frame->settings())
         return false;
 
     return frame->settings()->viewportMetaEnabled();
 }
 
 } // namespace blink