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

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.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 NGConstraintSpace_h
 #define NGConstraintSpace_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_units.h"
 #include "core/layout/ng/ng_writing_mode.h"
@@ skipping 49 matching lines @@
   // Return the block-direction space available in the current fragmentainer.
   LayoutUnit FragmentainerSpaceAvailable() const {
     DCHECK(HasBlockFragmentation());
     return fragmentainer_space_available_;
   }
 
   // Whether the current constraint space is for the newly established
   // Formatting Context.
   bool IsNewFormattingContext() const { return is_new_fc_; }
 
+  // Whether the fragment produced from layout should be anonymous, (e.g. it
+  // may be a column in a multi-column layout). In such cases it shouldn't have
+  // any borders or padding.
+  bool IsAnonymous() const { return is_anonymous_; }
+
   // Whether exceeding the AvailableSize() triggers the presence of a scrollbar
   // for the indicated direction.
   // If exceeded the current layout should be aborted and invoked again with a
   // constraint space modified to reserve space for a scrollbar.
   bool IsInlineDirectionTriggersScrollbar() const {
     return is_inline_direction_triggers_scrollbar_;
   }
 
   bool IsBlockDirectionTriggersScrollbar() const {
     return is_block_direction_triggers_scrollbar_;
@@ skipping 45 matching lines @@
                     NGLogicalSize percentage_resolution_size,
                     NGPhysicalSize initial_containing_block_size,
                     LayoutUnit fragmentainer_space_available,
                     bool is_fixed_size_inline,
                     bool is_fixed_size_block,
                     bool is_shrink_to_fit,
                     bool is_inline_direction_triggers_scrollbar,
                     bool is_block_direction_triggers_scrollbar,
                     NGFragmentationType block_direction_fragmentation_type,
                     bool is_new_fc,
+                    bool is_anonymous,
                     const NGMarginStrut& margin_strut,
                     const NGLogicalOffset& bfc_offset,
                     const std::shared_ptr<NGExclusions>& exclusions);
 
   NGPhysicalSize InitialContainingBlockSize() const {
     return initial_containing_block_size_;
   }
 
   NGLogicalSize available_size_;
   NGLogicalSize percentage_resolution_size_;
   NGPhysicalSize initial_containing_block_size_;
 
   LayoutUnit fragmentainer_space_available_;
 
   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 block_direction_fragmentation_type_ : 2;
 
   // Whether the current constraint space is for the newly established
   // formatting Context
   unsigned is_new_fc_ : 1;
+  unsigned is_anonymous_ : 1;

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

Should probably add a blank line above this, since it has nothing to do with the
comment above.

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

Done.

 
   unsigned writing_mode_ : 3;
   unsigned direction_ : 1;
 
   NGMarginStrut margin_strut_;
   NGLogicalOffset bfc_offset_;
   const std::shared_ptr<NGExclusions> exclusions_;
 };
 
 inline std::ostream& operator<<(std::ostream& stream,
                                 const NGConstraintSpace& value) {
   return stream << value.ToString();
 }
 
 }  // namespace blink
 
 #endif  // NGConstraintSpace_h