[LayoutNG] Initial support for multicol, introducing NGBlockBreakToken.

third_party/WebKit/Source/core/layout/ng/ng_physical_fragment.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 NGPhysicalFragment_h
 #define NGPhysicalFragment_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_units.h"
 #include "platform/LayoutUnit.h"
@@ skipping 43 matching lines @@
     return offset_.top;
   }
 
   // Should only be used by the parent fragement's layout.
   void SetOffset(NGPhysicalOffset offset) {
     DCHECK(!has_been_placed_);
     offset_ = offset;
     has_been_placed_ = true;
   }
 
+  NGBreakToken* BreakToken() const { return break_token_; }
+
   const HeapLinkedHashSet<WeakMember<NGBlockNode>>& OutOfFlowDescendants()
       const {
     return out_of_flow_descendants_;
   }
 
   const Vector<NGStaticPosition>& OutOfFlowPositions() const {
     return out_of_flow_positions_;
   }
 
   DECLARE_TRACE_AFTER_DISPATCH();
@@ skipping 17 matching lines @@
   HeapLinkedHashSet<WeakMember<NGBlockNode>> out_of_flow_descendants_;
   Vector<NGStaticPosition> out_of_flow_positions_;
 
   unsigned type_ : 1;
   unsigned has_been_placed_ : 1;
 };
 
 }  // namespace blink
 
 #endif  // NGPhysicalFragment_h