Move a static member function nodeIsUserSelectNone() out from PositionAlgorithm template class

Source/core/editing/EditingUtilities.cpp

Index: Source/core/editing/EditingUtilities.cpp
diff --git a/Source/core/editing/EditingUtilities.cpp b/Source/core/editing/EditingUtilities.cpp
index 313dfc53ac8416ec2b6aca471fd60549d21fec6d..127ab16c45a3d4390c454c93eb2ef306cf65dcc1 100644
--- a/Source/core/editing/EditingUtilities.cpp
+++ b/Source/core/editing/EditingUtilities.cpp
@@ -545,6 +545,11 @@ bool inSameContainingBlockFlowElement(Node* a, Node* b)
     return a && b && enclosingBlockFlowElement(*a) == enclosingBlockFlowElement(*b);
 }
 
+bool nodeIsUserSelectNone(Node* node)
+{
+    return node && node->layoutObject() && !node->layoutObject()->isSelectable();
+}
+
 TextDirection directionOfEnclosingBlock(const Position& position)
 {
     Element* enclosingBlockElement = enclosingBlock(position.computeContainerNode());