Keep a cache of caret painters to avoid recomputing all the time.

Source/core/paint/ReplicaPainter.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 "config.h"
 #include "core/paint/ReplicaPainter.h"
 
 #include "core/layout/LayoutReplica.h"
 #include "core/paint/DeprecatedPaintLayer.h"
 #include "core/paint/DeprecatedPaintLayerPainter.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/paint/PaintInfo.h"
 
 namespace blink {
 
 void ReplicaPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     if (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseMask)
         return;
 
     LayoutPoint adjustedPaintOffset = paintOffset + m_layoutReplica.location();
 
     if (paintInfo.phase == PaintPhaseForeground) {
         // Turn around and paint the parent layer. Use temporary clipRects, so that the layer doesn't end up caching clip rects
         // computing using the wrong rootLayer
         DeprecatedPaintLayer* rootPaintingLayer = m_layoutReplica.layer()->transform() ? m_layoutReplica.layer()->parent() : m_layoutReplica.layer()->enclosingTransformedAncestor();
-        DeprecatedPaintLayerPaintingInfo paintingInfo(rootPaintingLayer, LayoutRect(paintInfo.rect), PaintBehaviorNormal, LayoutSize(), 0);
+        DeprecatedPaintLayerPaintingInfo paintingInfo(rootPaintingLayer, LayoutRect(paintInfo.rect), PaintBehaviorNormal, LayoutSize(), 0, paintInfo.paintDataCache());
         PaintLayerFlags flags = PaintLayerHaveTransparency | PaintLayerAppliedTransform | PaintLayerUncachedClipRects | PaintLayerPaintingReflection;
         DeprecatedPaintLayerPainter(*m_layoutReplica.layer()->parent()).paintLayer(paintInfo.context, paintingInfo, flags);
     } else if (paintInfo.phase == PaintPhaseMask) {
         m_layoutReplica.paintMask(paintInfo, adjustedPaintOffset);
     }
 }
 
 } // namespace blink