Update from https://crrev.com/308331

sky/engine/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 31 matching lines @@
 #include "sky/engine/core/rendering/PaintInfo.h"
 #include "sky/engine/core/rendering/RenderFlexibleBox.h"
 #include "sky/engine/core/rendering/RenderInline.h"
 #include "sky/engine/core/rendering/RenderLayer.h"
 #include "sky/engine/core/rendering/RenderObjectInlines.h"
 #include "sky/engine/core/rendering/RenderParagraph.h"
 #include "sky/engine/core/rendering/RenderView.h"
 #include "sky/engine/core/rendering/style/RenderStyle.h"
 #include "sky/engine/platform/geometry/FloatQuad.h"
 #include "sky/engine/platform/geometry/TransformState.h"
-#include "sky/engine/platform/graphics/GraphicsContextCullSaver.h"
 #include "sky/engine/platform/graphics/GraphicsContextStateSaver.h"
 #include "sky/engine/wtf/StdLibExtras.h"
 #include "sky/engine/wtf/TemporaryChange.h"
 
 using namespace WTF;
 using namespace Unicode;
 
 namespace blink {
 
 struct SameSizeAsRenderBlock : public RenderBox {
@@ skipping 527 matching lines @@
     }
 
     // There are some cases where not all clipped visual overflow is accounted for.
     // FIXME: reduce the number of such cases.
     ContentsClipBehavior contentsClipBehavior = ForceContentsClip;
     if (hasOverflowClip() && !hasControlClip() && !(shouldPaintSelectionGaps() && phase == PaintPhaseForeground) && !hasCaret())
         contentsClipBehavior = SkipContentsClipIfPossible;
 
     bool pushedClip = pushContentsClip(paintInfo, adjustedPaintOffset, contentsClipBehavior);
     {
-        GraphicsContextCullSaver cullSaver(*paintInfo.context);
-        // Cull if we have more than one child and we didn't already clip.
-        bool shouldCull = document().settings()->containerCullingEnabled() && !pushedClip && !isDocumentElement()
-            && firstChild() && lastChild() && firstChild() != lastChild();
-        if (shouldCull)
-            cullSaver.cull(overflowBox);
-
         paintObject(paintInfo, adjustedPaintOffset);
     }
     if (pushedClip)
         popContentsClip(paintInfo, phase, adjustedPaintOffset);
 
     // Our scrollbar widgets paint exactly when we tell them to, so that they work properly with
     // z-index.  We paint after we painted the background/border, so that the scrollbars will
     // sit above the background/border.
     if (hasOverflowClip() && (phase == PaintPhaseBlockBackground || phase == PaintPhaseChildBlockBackground) && paintInfo.shouldPaintWithinRoot(this))
         layer()->scrollableArea()->paintOverflowControls(paintInfo.context, roundedIntPoint(adjustedPaintOffset), paintInfo.rect, false /* paintingOverlayControls */);
@@ skipping 1427 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink