[LayoutNG] Initial support for multicol, introducing NGBlockBreakToken.

third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.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 NGConstraintSpaceBuilder_h
 #define NGConstraintSpaceBuilder_h
 
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_units.h"
 
 namespace blink {
 
 class CORE_EXPORT NGConstraintSpaceBuilder final
     : public GarbageCollectedFinalized<NGConstraintSpaceBuilder> {
  public:
   NGConstraintSpaceBuilder(const NGConstraintSpace* parent_space);
 
   NGConstraintSpaceBuilder(NGWritingMode writing_mode);
 
   NGConstraintSpaceBuilder& SetAvailableSize(NGLogicalSize available_size);
 
   NGConstraintSpaceBuilder& SetPercentageResolutionSize(
       NGLogicalSize percentage_resolution_size);
 
+  NGConstraintSpaceBuilder& SetFragmentainerSpaceAvailable(LayoutUnit space) {
+    fragmentainer_space_available_ = space;
+    return *this;
+  }
+
   NGConstraintSpaceBuilder& SetTextDirection(TextDirection);
 
   NGConstraintSpaceBuilder& SetIsFixedSizeInline(bool is_fixed_size_inline);
   NGConstraintSpaceBuilder& SetIsFixedSizeBlock(bool is_fixed_size_block);
 
   NGConstraintSpaceBuilder& SetIsShrinkToFit(bool shrink_to_fit);
 
   NGConstraintSpaceBuilder& SetIsInlineDirectionTriggersScrollbar(
       bool is_inline_direction_triggers_scrollbar);
   NGConstraintSpaceBuilder& SetIsBlockDirectionTriggersScrollbar(
@@ skipping 10 matching lines @@
   //  - Is within a fragmentation container and needs its fragmentation offset
   //    updated.
   //  - Has its size is determined by its parent layout (flex, abs-pos).
   NGConstraintSpace* ToConstraintSpace();
 
   DEFINE_INLINE_TRACE() {}
 
  private:
   NGLogicalSize available_size_;
   NGLogicalSize percentage_resolution_size_;
+  LayoutUnit fragmentainer_space_available_;
 
   unsigned writing_mode_ : 2;
   unsigned parent_writing_mode_ : 2;
   unsigned is_fixed_size_inline_ : 1;
   unsigned is_fixed_size_block_ : 1;
   unsigned is_shrink_to_fit_ : 1;
   unsigned is_inline_direction_triggers_scrollbar_ : 1;
   unsigned is_block_direction_triggers_scrollbar_ : 1;
   unsigned fragmentation_type_ : 2;
   unsigned is_new_fc_ : 1;
   unsigned text_direction_ : 1;
 
   std::shared_ptr<NGExclusions> exclusions_;
 };
 
 }  // namespace blink
 
 #endif  // NGConstraintSpaceBuilder