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

Source/core/paint/DeprecatedPaintLayerPainter.cpp

Index: Source/core/paint/DeprecatedPaintLayerPainter.cpp
diff --git a/Source/core/paint/DeprecatedPaintLayerPainter.cpp b/Source/core/paint/DeprecatedPaintLayerPainter.cpp
index 7022f48e765f3195acb539b842ebb9e6036a7af1..2119565622f5b1033edb6b0d640cc31ca2b00c88 100644
--- a/Source/core/paint/DeprecatedPaintLayerPainter.cpp
+++ b/Source/core/paint/DeprecatedPaintLayerPainter.cpp
@@ -16,6 +16,7 @@
 #include "core/paint/FilterPainter.h"
 #include "core/paint/LayerClipRecorder.h"
 #include "core/paint/LayerFixedPositionRecorder.h"
+#include "core/paint/PaintDataCache.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/SVGClipPainter.h"
 #include "core/paint/ScopeRecorder.h"
@@ -44,7 +45,8 @@ static inline bool shouldSuppressPaintingLayer(DeprecatedPaintLayer* layer)
 
 void DeprecatedPaintLayerPainter::paint(GraphicsContext* context, const LayoutRect& damageRect, PaintBehavior paintBehavior, LayoutObject* paintingRoot, PaintLayerFlags paintFlags)
 {
-    DeprecatedPaintLayerPaintingInfo paintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(damageRect)), paintBehavior, LayoutSize(), paintingRoot);
+    PaintDataCache paintDataCache;
+    DeprecatedPaintLayerPaintingInfo paintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(damageRect)), paintBehavior, LayoutSize(), paintingRoot, &paintDataCache);
     if (shouldPaintLayerInSoftwareMode(paintingInfo, paintFlags))
         paintLayer(context, paintingInfo, paintFlags);
 }
@@ -407,7 +409,7 @@ void DeprecatedPaintLayerPainter::paintFragmentByApplyingTransform(GraphicsConte
 
     // Now do a paint with the root layer shifted to be us.
     DeprecatedPaintLayerPaintingInfo transformedPaintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(transform.inverse().mapRect(paintingInfo.paintDirtyRect))), paintingInfo.paintBehavior,
-        adjustedSubPixelAccumulation, paintingInfo.paintingRoot);
+        adjustedSubPixelAccumulation, paintingInfo.paintingRoot, paintingInfo.paintDataCache);
     paintLayerContentsAndReflection(context, transformedPaintingInfo, paintFlags, ForceSingleFragment);
 }
 
@@ -499,7 +501,7 @@ void DeprecatedPaintLayerPainter::paintFragmentWithPhase(PaintPhase phase, const
         clipRecorder.emplace(*context, *m_paintLayer.layoutObject(), clipType, clipRect, &paintingInfo, fragment.paginationOffset, paintFlags, clippingRule);
     }
 
-    PaintInfo paintInfo(context, pixelSnappedIntRect(clipRect.rect()), phase, paintBehavior, paintingRootForLayoutObject, 0, paintingInfo.rootLayer->layoutObject());
+    PaintInfo paintInfo(context, pixelSnappedIntRect(clipRect.rect()), phase, paintBehavior, paintingRootForLayoutObject, 0, paintingInfo.rootLayer->layoutObject(), paintingInfo.paintDataCache);
     OwnPtr<ScrollRecorder> scrollRecorder;
     LayoutPoint paintOffset = toPoint(fragment.layerBounds.location() - m_paintLayer.layoutBoxLocation());
     if (!paintingInfo.scrollOffsetAccumulation.isZero()) {