Make scroll translation transform nodes reference scroll nodes

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/ScrollPaintPropertyNode.h"
@@ skipping 109 matching lines @@
 
 #if DCHECK_IS_ON()
   // Dumps the tree from this state up to the root as a string.
   String toTreeString() const;
 #endif
 
  private:
   RefPtr<const TransformPaintPropertyNode> m_transform;
   RefPtr<const ClipPaintPropertyNode> m_clip;
   RefPtr<const EffectPaintPropertyNode> m_effect;
+  // TODO(pdr): Remove the scroll node from PropertyTreeState.
   RefPtr<const ScrollPaintPropertyNode> m_scroll;
 };
 
 inline bool operator==(const PropertyTreeState& a, const PropertyTreeState& b) {
   return a.transform() == b.transform() && a.clip() == b.clip() &&
          a.effect() == b.effect() && a.scroll() == b.scroll();
 }
 
 // Iterates over the sequence transforms, clips and effects for a
 // PropertyTreeState between that state and the "root" state (all nodes equal
@@ skipping 51 matching lines @@
   }
 
   HashMap<const PropertyTreeNode*, String> m_nodeToDebugString;
 };
 
 #endif
 
 }  // namespace blink
 
 #endif  // PropertyTreeState_h