Make isEditablePosition to work with Position objects other than PositionIsOffsetInAnchor

Source/core/editing/htmlediting.cpp

Index: Source/core/editing/htmlediting.cpp
diff --git a/Source/core/editing/htmlediting.cpp b/Source/core/editing/htmlediting.cpp
index 6c7b309faf972a3ab3f1ef79fcc17fbb298bb8aa..cde332cc6ccddc1d6808bc4bdfab34fd7240ff19 100644
--- a/Source/core/editing/htmlediting.cpp
+++ b/Source/core/editing/htmlediting.cpp
@@ -154,7 +154,7 @@ Node* lowestEditableAncestor(Node* node)
 
 bool isEditablePosition(const Position& p, EditableType editableType, EUpdateStyle updateStyle)
 {
-    Node* node = p.deprecatedNode();
+    Node* node = p.parentAnchoredEquivalent().anchorNode();
     if (!node)
         return false;
     if (updateStyle == UpdateStyle)