[LayoutNG] PODify NGLayoutInputNode and sub-classes.

third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h

 // Copyright 2016 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.
 
 #ifndef NGLayoutAlgorithm_h
 #define NGLayoutAlgorithm_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_floats_utils.h"
 #include "core/layout/ng/ng_fragment_builder.h"
 #include "core/layout/ng/ng_min_max_content_size.h"
 #include "platform/wtf/Allocator.h"
 #include "platform/wtf/Optional.h"
 
 namespace blink {
 
 class ComputedStyle;
 class NGConstraintSpace;
 class NGLayoutResult;
 
 // Base class for all LayoutNG algorithms.
 template <typename NGInputNodeType, typename NGBreakTokenType>
 class CORE_EXPORT NGLayoutAlgorithm {
   STACK_ALLOCATED();
  public:
-  NGLayoutAlgorithm(NGInputNodeType* node,
+  NGLayoutAlgorithm(NGInputNodeType node,
                     NGConstraintSpace* space,
                     NGBreakTokenType* break_token)
       : node_(node),
         constraint_space_(space),
         break_token_(break_token),
         container_builder_(NGPhysicalFragment::kFragmentBox, node) {}
 
   virtual ~NGLayoutAlgorithm() {}
 
   // Actual layout function. Lays out the children and descendants within the
@@ skipping 11 matching lines @@
     return WTF::nullopt;
   }
 
  protected:
   const NGConstraintSpace& ConstraintSpace() const {
     DCHECK(constraint_space_);
     return *constraint_space_;
   }
   NGConstraintSpace* MutableConstraintSpace() { return constraint_space_; }
 
-  const ComputedStyle& Style() const {
-    DCHECK(node_);
-    return node_->Style();
-  }
+  const ComputedStyle& Style() const { return node_.Style(); }
 
   NGLogicalOffset ContainerBfcOffset() const {
     DCHECK(container_builder_.BfcOffset().has_value());
     return container_builder_.BfcOffset().value();
   }
 
-  virtual NGInputNodeType* Node() const { return node_; }
+  virtual NGInputNodeType Node() const { return node_; }
 
   NGBreakTokenType* BreakToken() const { return break_token_; }
 
-  Persistent<NGInputNodeType> node_;
+  NGInputNodeType node_;
   NGConstraintSpace* constraint_space_;
 
   // The break token from which we are currently resuming layout.
   NGBreakTokenType* break_token_;
 
   NGFragmentBuilder container_builder_;
 };
 
 }  // namespace blink
 
 #endif  // NGLayoutAlgorithm_h