Make VisiblePosition::BeforeNode() to take const Node& instead of Node*

third_party/WebKit/Source/core/editing/VisiblePosition.h

 /*
  * Copyright (C) 2004, 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 87 matching lines @@
   }
   PositionTemplate<Strategy> ToParentAnchoredPosition() const {
     return DeepEquivalent().ParentAnchoredEquivalent();
   }
   PositionWithAffinityTemplate<Strategy> ToPositionWithAffinity() const {
     return position_with_affinity_;
   }
   TextAffinity Affinity() const { return position_with_affinity_.Affinity(); }
 
   static VisiblePositionTemplate<Strategy> AfterNode(const Node&);
-  static VisiblePositionTemplate<Strategy> BeforeNode(Node*);
+  static VisiblePositionTemplate<Strategy> BeforeNode(const Node&);
   static VisiblePositionTemplate<Strategy> FirstPositionInNode(Node*);
   static VisiblePositionTemplate<Strategy> InParentAfterNode(const Node&);
   static VisiblePositionTemplate<Strategy> InParentBeforeNode(const Node&);
   static VisiblePositionTemplate<Strategy> LastPositionInNode(Node*);
 
   DECLARE_TRACE();
 
 #ifndef NDEBUG
   void ShowTreeForThis() const;
 #endif
@@ skipping 34 matching lines @@
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const blink::VisiblePosition*);
 void showTree(const blink::VisiblePosition&);
 #endif
 
 #endif  // VisiblePosition_h