Add background attachment fixed main thread scrolling reason [spv2]

third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h

 // 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.
 
 #ifndef PaintPropertyTreeBuilder_h
 #define PaintPropertyTreeBuilder_h
 
 #include "platform/geometry/LayoutPoint.h"
 #include "platform/graphics/paint/ClipPaintPropertyNode.h"
 #include "platform/graphics/paint/EffectPaintPropertyNode.h"
@@ skipping 29 matching lines @@
         // TransformPaintPropertyNode::renderingContextID.
         unsigned renderingContextID = 0;
         // The clip node describes the accumulated raster clip for the current subtree.
         // Note that the computed raster region in canvas space for a clip node is independent from
         // the transform and paint offset above. Also the actual raster region may be affected
         // by layerization and occlusion tracking.
         const ClipPaintPropertyNode* clip = nullptr;
         // The scroll node contains information for scrolling such as the parent scroll space, the
         // extent that can be scrolled, etc. Because scroll nodes reference a scroll offset
         // transform, scroll nodes should be updated if the transform tree changes.
-        const ScrollPaintPropertyNode* scroll = nullptr;
+        ScrollPaintPropertyNode* scroll = nullptr;
     };
 
     ContainingBlockContext current;
 
     // Separate context for out-of-flow positioned and fixed positioned elements are needed
     // because they don't use DOM parent as their containing block.
     // These additional contexts normally pass through untouched, and are only copied from
     // the main context when the current element serves as the containing block of corresponding
     // positioned descendants.
     // Overflow clips are also inherited by containing block tree instead of DOM tree, thus they
@@ skipping 20 matching lines @@
     void buildTreeNodesForSelf(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     void buildTreeNodesForChildren(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
 private:
     static void updatePaintOffsetTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateEffect(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateCssClip(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateLocalBorderBoxContext(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateScrollbarPaintOffset(const LayoutObject&, const PaintPropertyTreeBuilderContext&);
+    static void updateMainThreadScrollingReasons(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateOverflowClip(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updatePerspective(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateSvgLocalToBorderBoxTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateScrollAndScrollTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&);
     static void updateOutOfFlowContext(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 };
 
 } // namespace blink
 
 #endif // PaintPropertyTreeBuilder_h