Remove tons of OILPAN.

sky/engine/core/editing/VisibleSelection.cpp

Index: sky/engine/core/editing/VisibleSelection.cpp
diff --git a/sky/engine/core/editing/VisibleSelection.cpp b/sky/engine/core/editing/VisibleSelection.cpp
index 742ff2daa782afc23c3c5698d1e06276036cb80e..a48f13ebc71512c72f075aee2b182588f66581ec 100644
--- a/sky/engine/core/editing/VisibleSelection.cpp
+++ b/sky/engine/core/editing/VisibleSelection.cpp
@@ -761,15 +761,6 @@ void VisibleSelection::didChange()
         m_changeObserver->didChangeVisibleSelection();
 }
 
-void VisibleSelection::trace(Visitor* visitor)
-{
-    visitor->trace(m_base);
-    visitor->trace(m_extent);
-    visitor->trace(m_start);
-    visitor->trace(m_end);
-    visitor->trace(m_changeObserver);
-}
-
 static bool isValidPosition(const Position& position)
 {
     if (!position.inDocument())