[LayoutNG] Add NGInlineBreakToken and back of NGInlineLayoutAlgorithm

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

 // 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.
 
 #ifndef NGLineBoxFragmentBuilder_h
 #define NGLineBoxFragmentBuilder_h
 
 #include "core/layout/ng/geometry/ng_logical_offset.h"
 #include "core/layout/ng/ng_line_height_metrics.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
+class NGInlineBreakToken;
 class NGInlineNode;
 class NGPhysicalFragment;
 class NGPhysicalLineBoxFragment;
 
 class CORE_EXPORT NGLineBoxFragmentBuilder final {
   STACK_ALLOCATED();
 
  public:
   NGLineBoxFragmentBuilder(NGInlineNode*);
 
   NGLineBoxFragmentBuilder& SetDirection(TextDirection);
 
   NGLineBoxFragmentBuilder& SetInlineSize(LayoutUnit);
 
   NGLineBoxFragmentBuilder& AddChild(RefPtr<NGPhysicalFragment>,
                                      const NGLogicalOffset&);
   void MoveChildrenInBlockDirection(LayoutUnit);
 
   const Vector<RefPtr<NGPhysicalFragment>>& Children() const {
     return children_;
   }
 
   void UniteMetrics(const NGLineHeightMetrics&);
   const NGLineHeightMetrics& Metrics() const { return metrics_; }
 
+  // Set the break token for the fragment to build.
+  // A finished break token will be attached if not set.
+  void SetBreakToken(RefPtr<NGInlineBreakToken>);
+
   // Creates the fragment. Can only be called once.
   RefPtr<NGPhysicalLineBoxFragment> ToLineBoxFragment();
 
  private:
   TextDirection direction_;
 
   Persistent<NGInlineNode> node_;
 
   LayoutUnit inline_size_;
 
   Vector<RefPtr<NGPhysicalFragment>> children_;
   Vector<NGLogicalOffset> offsets_;
 
   NGLineHeightMetrics metrics_;
+
+  RefPtr<NGInlineBreakToken> break_token_;
 };
 
 }  // namespace blink
 
 #endif  // NGLineBoxFragmentBuilder