[LayoutNG] Handle empty inlines and border edges

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_layout_algorithm.cc

 // 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.
 
 #include "core/layout/ng/inline/ng_inline_layout_algorithm.h"
 
 #include "core/layout/ng/inline/ng_bidi_paragraph.h"
 #include "core/layout/ng/inline/ng_inline_break_token.h"
 #include "core/layout/ng/inline/ng_inline_node.h"
 #include "core/layout/ng/inline/ng_line_box_fragment.h"
@@ skipping 241 matching lines @@
                                       item_result.end_offset);
       line_box.AddChild(std::move(text_fragment), {position, box->text_top});
     } else if (item.Type() == NGInlineItem::kOpenTag) {
       box = box_states_.OnOpenTag(item, &line_box);
       // Compute text metrics for all inline boxes since even empty inlines
       // influence the line height.
       // https://drafts.csswg.org/css2/visudet.html#line-height
       box->ComputeTextMetrics(*item.Style(), baseline_type_);
       text_builder.SetDirection(box->style->Direction());
       // TODO(kojii): We may need more conditions to create box fragments.
-      if (item.Style()->HasBoxDecorationBackground()) {
-        // TODO(kojii): These are once computed in NGLineBreaker. Should copy to
-        // NGInlineItemResult to reuse here.
-        NGBoxStrut borders = ComputeBorders(*constraint_space_, *item.Style());
-        NGBoxStrut paddings = ComputePadding(*constraint_space_, *item.Style());
-        // TODO(kojii): Set paint edges.
-        box->SetNeedsBoxFragment(position,
-                                 borders.block_start + paddings.block_start,
-                                 borders.BlockSum() + paddings.BlockSum());
-      }
+      if (item.Style()->HasBoxDecorationBackground())
+        box->SetNeedsBoxFragment(item, item_result, position);
     } else if (item.Type() == NGInlineItem::kCloseTag) {
       position += item_result.inline_size;
-      box = box_states_.OnCloseTag(item, &line_box, box, baseline_type_,
-                                   position);
+      if (box->needs_box_fragment)
+        box->SetLineRightForBoxFragment(item, item_result, position);
+      box = box_states_.OnCloseTag(item, &line_box, box, baseline_type_);
       continue;
     } else if (item.Type() == NGInlineItem::kAtomicInline) {
       box = PlaceAtomicInline(item, &item_result, position, &line_box,
                               &text_builder);
     } else if (item.Type() == NGInlineItem::kOutOfFlowPositioned) {
       // TODO(layout-dev): Report the correct static position for the out of
       // flow descendant. We can't do this here yet as it doesn't know the
       // size of the line box.
       container_builder_.AddOutOfFlowDescendant(
           // Absolute positioning blockifies the box's display type.
@@ skipping 94 matching lines @@
   // |fragment| directly. Currently |CopyFragmentDataToLayoutBlockFlow|
   // requires a text fragment.
   text_builder->SetDirection(item.Style()->Direction());
   text_builder->SetSize({fragment.InlineSize(), block_size});
   LayoutUnit line_top = item_result->margins.block_start - metrics.ascent;
   RefPtr<NGPhysicalTextFragment> text_fragment = text_builder->ToTextFragment(
       item_result->item_index, item_result->start_offset,
       item_result->end_offset);
   line_box->AddChild(std::move(text_fragment), {position, line_top});
 
-  return box_states_.OnCloseTag(item, line_box, box, baseline_type_,
-                                LayoutUnit(0));
+  return box_states_.OnCloseTag(item, line_box, box, baseline_type_);
 }
 
 void NGInlineLayoutAlgorithm::ApplyTextAlign(LayoutUnit* line_left,
                                              LayoutUnit inline_size,
                                              LayoutUnit available_width) {
   // TODO(kojii): Implement text-align-last.
   ETextAlign text_align = LineStyle().GetTextAlign();
   switch (text_align) {
     case ETextAlign::kRight:
     case ETextAlign::kWebkitRight:
@@ skipping 53 matching lines @@
   // Margin struts shouldn't need to be passed through like this once we've
   // removed LayoutInline splitting.
   if (!container_builder_.BfcOffset()) {
     container_builder_.SetEndMarginStrut(ConstraintSpace().MarginStrut());
   }
 
   return container_builder_.ToBoxFragment();
 }
 
 }  // namespace blink