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

third_party/WebKit/Source/core/editing/spellcheck/ColdModeSpellCheckRequester.cpp

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/editing/spellcheck/ColdModeSpellCheckRequester.h"
 
 #include "core/dom/Element.h"
 #include "core/dom/IdleDeadline.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/VisibleUnits.h"
 #include "core/editing/iterators/CharacterIterator.h"
 #include "core/editing/spellcheck/SpellCheckRequester.h"
 #include "core/editing/spellcheck/SpellChecker.h"
 #include "core/frame/LocalFrame.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
 
 namespace blink {
 
 namespace {
 
 const int kColdModeChunkSize = 16384;  // in UTF16 code units
 const int kInvalidLength = -1;
 const int kInvalidChunkIndex = -1;
 
 bool ShouldCheckNode(const Node& node) {
   if (!node.IsElementNode())
     return false;
   // TODO(editing-dev): Make |Position| constructors take const parameters.
-  const Position& position =
-      Position::FirstPositionInNode(const_cast<Node*>(&node));
+  const Position& position = Position::FirstPositionInNode(node);
   if (!IsEditablePosition(position))
     return false;
   return SpellChecker::IsSpellCheckingEnabledAt(position);
 }
 
 }  // namespace
 
 // static
 ColdModeSpellCheckRequester* ColdModeSpellCheckRequester::Create(
     LocalFrame& frame) {
@@ skipping 133 matching lines @@
   next_node_ = FlatTreeTraversal::NextSkippingChildren(
       *next_node_, GetFrame().GetDocument()->body());
 
   current_root_editable_ = nullptr;
   current_full_length_ = kInvalidLength;
   current_chunk_index_ = kInvalidChunkIndex;
   current_chunk_start_ = Position();
 }
 
 }  // namespace blink