Ignore scroll node when checking whether a chunk can merge.

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

Index: third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.cpp b/third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.cpp
index c350165afdf9f5b5e9b38841ea35bf4682d9d76d..d75eafdce615352ba9c270de72485ede147bd237 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.cpp
@@ -59,6 +59,12 @@ const CompositorElementId PropertyTreeState::compositorElementId() const {
   return CompositorElementId();
 }
 
+bool PropertyTreeState::equivalentGeometry(
+    const PropertyTreeState& other) const {
+  return transform() == other.transform() && clip() == other.clip() &&
+         effect() == other.effect();
+}
+
 PropertyTreeState::InnermostNode PropertyTreeState::innermostNode() const {
   // TODO(chrishtr): this is very inefficient when innermostNode() is called
   // repeatedly.