[LayoutNG] Move NGConstraintSpaceBuilder off Oilpan and DISALLOW_NEW.

third_party/WebKit/Source/core/layout/ng/ng_block_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 NGBlockLayoutAlgorithm_h
 #define NGBlockLayoutAlgorithm_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_block_node.h"
 #include "core/layout/ng/ng_break_token.h"
+#include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_fragment_builder.h"
 #include "core/layout/ng/ng_layout_algorithm.h"
 #include "core/layout/ng/ng_units.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
 class ComputedStyle;
 class NGBlockBreakToken;
 class NGConstraintSpace;
-class NGConstraintSpaceBuilder;
 class NGInlineNode;
 class NGLayoutResult;
 
 // A class for general block layout (e.g. a <div> with no special style).
 // Lays out the children in sequence.
 class CORE_EXPORT NGBlockLayoutAlgorithm : public NGLayoutAlgorithm {
  public:
   // Default constructor.
   // @param node The input node to perform layout upon.
   // @param space The constraint space which the algorithm should generate a
@@ skipping 43 matching lines @@
   }
 
   const ComputedStyle& Style() const { return node_->Style(); }
 
   Persistent<NGBlockNode> node_;
   Persistent<NGConstraintSpace> constraint_space_;
 
   // The break token from which we are currently resuming layout.
   Persistent<NGBlockBreakToken> break_token_;
 
-  std::unique_ptr<NGFragmentBuilder> builder_;
-  Persistent<NGConstraintSpaceBuilder> space_builder_;
+  NGFragmentBuilder builder_;
+  NGConstraintSpaceBuilder space_builder_;
 
   NGBoxStrut border_and_padding_;
   LayoutUnit content_size_;
   LayoutUnit max_inline_size_;
   // MarginStrut for the previous child.
   NGMarginStrut curr_margin_strut_;
   NGLogicalOffset curr_bfc_offset_;
   NGBoxStrut curr_child_margins_;
 };
 
 }  // namespace blink
 
 #endif  // NGBlockLayoutAlgorithm_h