[LayoutNG] Allow block-flow layout to be fragmented using new approach.

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"
 
@@ skipping 25 matching lines @@
 
   NGConstraintSpaceBuilder& SetIsShrinkToFit(bool shrink_to_fit);
 
   NGConstraintSpaceBuilder& SetIsInlineDirectionTriggersScrollbar(
       bool is_inline_direction_triggers_scrollbar);
   NGConstraintSpaceBuilder& SetIsBlockDirectionTriggersScrollbar(
       bool is_block_direction_triggers_scrollbar);
 
   NGConstraintSpaceBuilder& SetFragmentationType(NGFragmentationType);
   NGConstraintSpaceBuilder& SetIsNewFormattingContext(bool is_new_fc);
+  NGConstraintSpaceBuilder& SetIsAnonymous(bool is_anonymous);

[mstensho (USE GERRIT), 2017/02/27 13:44:36]

Does it ever make sense to pass false here? I.e. could we just remove the
parameter, perhaps?

[ikilpatrick, 2017/02/27 18:50:09]

So the constraint space builder can be re-used for multiple children. In
multi-cols case, if we see a spanner we'll probably want to set this to false?

[mstensho (USE GERRIT), 2017/02/27 20:28:20]

Acknowledged.

 
   NGConstraintSpaceBuilder& SetMarginStrut(const NGMarginStrut& margin_strut);
 
   NGConstraintSpaceBuilder& SetBfcOffset(const NGLogicalOffset& offset) {
     bfc_offset_ = offset;
     return *this;
   }
 
   // Creates a new constraint space. This may be called multiple times, for
   // example the constraint space will be different for a child which:
@@ skipping 16 matching lines @@
   LayoutUnit fragmentainer_space_available_;
 
   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 is_anonymous_ : 1;
   unsigned text_direction_ : 1;
 
   NGMarginStrut margin_strut_;
   NGLogicalOffset bfc_offset_;
   std::shared_ptr<NGExclusions> exclusions_;
 };
 
 }  // namespace blink
 
 #endif  // NGConstraintSpaceBuilder