Store local border box property cache outside ObjectPaintProperties

third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp

 // Copyright 2015 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 "core/paint/PrePaintTreeWalk.h"
 
 #include "core/dom/DocumentLifecycle.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/LayoutMultiColumnSpannerPlaceholder.h"
@@ skipping 135 matching lines @@
     PrePaintTreeWalkContext& context) {
   if (!object.hasLayer())
     return;
 
   PaintLayer& paintLayer = *toLayoutBoxModelObject(object).layer();
   if (object.styleRef().hasTransform() ||
       &object == context.paintInvalidatorContext.paintInvalidationContainer) {
     context.ancestorTransformedOrRootPaintLayer = &paintLayer;
   }
 
-  const ObjectPaintProperties& ancestorPaintProperties =
-      *context.ancestorTransformedOrRootPaintLayer->layoutObject()
-           .paintProperties();
-  PropertyTreeState ancestorState =
-      *ancestorPaintProperties.localBorderBoxProperties();
+  const auto& ancestor =
+      context.ancestorTransformedOrRootPaintLayer->layoutObject();
+  PropertyTreeState ancestorState = *ancestor.localBorderBoxProperties();
 
 #ifdef CHECK_CLIP_RECTS
   ShouldRespectOverflowClipType respectOverflowClip = RespectOverflowClip;
 #endif
   if (context.ancestorTransformedOrRootPaintLayer->compositingState() ==
-          PaintsIntoOwnBacking &&
-      ancestorPaintProperties.overflowClip()) {
-    ancestorState.setClip(ancestorPaintProperties.overflowClip());
+      PaintsIntoOwnBacking) {
+    const auto* ancestorProperties = ancestor.paintProperties();
+    if (ancestorProperties && ancestorProperties->overflowClip()) {
+      ancestorState.setClip(ancestorProperties->overflowClip());
 #ifdef CHECK_CLIP_RECTS
-    respectOverflowClip = IgnoreOverflowClip;
+      respectOverflowClip = IgnoreOverflowClip;
 #endif
+    }
   }
 
 #ifdef CHECK_CLIP_RECTS
   ClipRects& oldClipRects =
       paintLayer.clipper(PaintLayer::DoNotUseGeometryMapper)
           .paintingClipRects(&ancestorTransformedOrRootPaintLayer,
                              respectOverflowClip, LayoutSize());
 #endif
 
   bool hasClip = false;
@@ skipping 98 matching lines @@
           roundedIntPoint(context.treeBuilderContext->current.paintOffset);
       walk(*toFrameView(frameViewBase), context);
     }
     // TODO(pdr): Investigate RemoteFrameView (crbug.com/579281).
   }
 
   object.getMutableForPainting().clearPaintFlags();
 }
 
 }  // namespace blink