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

third_party/WebKit/Source/core/editing/VisibleUnitsParagraph.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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
@@ skipping 35 matching lines @@
 template <typename Strategy>
 PositionTemplate<Strategy> StartOfParagraphAlgorithm(
     const PositionTemplate<Strategy>& position,
     EditingBoundaryCrossingRule boundary_crossing_rule) {
   Node* const start_node = position.AnchorNode();
 
   if (!start_node)
     return PositionTemplate<Strategy>();
 
   if (IsRenderedAsNonInlineTableImageOrHR(start_node))
-    return PositionTemplate<Strategy>::BeforeNode(start_node);
+    return PositionTemplate<Strategy>::BeforeNode(*start_node);
 
   Element* const start_block = EnclosingBlock(
       PositionTemplate<Strategy>::FirstPositionInOrBeforeNode(start_node),
       kCannotCrossEditingBoundary);
   ContainerNode* const highest_root = HighestEditableRoot(position);
   const bool start_node_is_editable = HasEditableStyle(*start_node);
 
   Node* candidate_node = start_node;
   PositionAnchorType candidate_type = position.AnchorType();
   int candidate_offset = position.ComputeEditingOffset();
@@ skipping 332 matching lines @@
           ? paragraph_start
           : range.StartPosition();
   const Position& result_end =
       paragraph_end.IsNotNull() && paragraph_end >= range.EndPosition()
           ? paragraph_end
           : range.EndPosition();
   return EphemeralRange(result_start, result_end);
 }
 
 }  // namespace blink