Ignore scroll node when checking whether a chunk can merge.

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 56 matching lines @@
   }
   void setScroll(RefPtr<const ScrollPaintPropertyNode> node) {
     m_scroll = std::move(node);
   }
 
   // Returns the compositor element id, if any, for this property state. If none
   // of the scroll, effect or transform nodes for this state have a compositor
   // element id then a default instance is returned.
   const CompositorElementId compositorElementId() const;
 
+  // Returns equivalence of transform, clip and effect nodes. We explicitly
+  // ignore the scroll node state as it is not relevant for straight geometry
+  // calculation purposes.
+  bool equivalentGeometry(const PropertyTreeState& other) const;
+
   enum InnermostNode {
     None,  // None means that all nodes are their root values
     Transform,
     Clip,
     Effect,
   };
 
   // There is always a well-defined order in which the transform, clip
   // and effects of a PropertyTreeState apply. This method returns which
   // of them applies first to content drawn with this PropertyTreeState.
@@ skipping 104 matching lines @@
   }
 
   HashMap<const PropertyTreeNode*, String> m_nodeToDebugString;
 };
 
 #endif
 
 }  // namespace blink
 
 #endif  // PropertyTreeState_h