[SPv2] Flatten property trees in PaintRecordBuilder into a single display list.

third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.h

 // Copyright 2016 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 PropertyTreeState_h
 #define PropertyTreeState_h
 
 #include "platform/graphics/paint/ClipPaintPropertyNode.h"
 #include "platform/graphics/paint/EffectPaintPropertyNode.h"
 #include "platform/graphics/paint/TransformPaintPropertyNode.h"
@@ skipping 37 matching lines @@
   }
 
   const EffectPaintPropertyNode* effect() const {
     DCHECK(!m_effect || !m_effect->hasOneRef());
     return m_effect.get();
   }
   void setEffect(RefPtr<const EffectPaintPropertyNode> node) {
     m_effect = std::move(node);
   }
 
+  static const PropertyTreeState& root();
+
   // Returns the compositor element id, if any, for this property state. If
   // neither the effect nor transform nodes have a compositor element id then a
   // default instance is returned.
   const CompositorElementId compositorElementId() const;
 
   enum InnermostNode {
     None,  // None means that all nodes are their root values
     Transform,
     Clip,
     Effect,
@@ skipping 108 matching lines @@
   }
 
   HashMap<const PropertyTreeNode*, String> m_nodeToDebugString;
 };
 
 #endif
 
 }  // namespace blink
 
 #endif  // PropertyTreeState_h