[LayoutNG] Refactor NGOutOfFlowLayoutPart member variables

NGOutOfFlowLayoutPart used to have a single containing block,
and it was defined by a NGOOFLP member variables.

With inline containing blocks, we have multiple containing blocks,
defined by ContainingBlockInfo.

This CL moves definition of default containing block out of multiple
member variables into single ContainingBlockInfo.

Bug: 635619
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I69dd499cb69c7e6fc56971e85882cd7e6241f99c
Reviewed-on: https://chromium-review.googlesource.com/829888Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Aleks Totic <atotic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524455}

third_party/WebKit/Source/core/layout/ng/ng_out_of_flow_layout_part.cc

@@ -23,28 +23,28 @@ NGOutOfFlowLayoutPart::NGOutOfFlowLayoutPart(
     const NGConstraintSpace& container_space,
     const ComputedStyle& container_style,
     NGFragmentBuilder* container_builder)
-    : container_style_(container_style),
-      container_builder_(container_builder),
+    : container_builder_(container_builder),
       contains_absolute_(container.IsAbsoluteContainer()),
       contains_fixed_(container.IsFixedContainer()) {
-  WritingMode writing_mode(container_style_.GetWritingMode());
-
-  NGBoxStrut borders = ComputeBorders(container_space, container_style_);
-  NGBoxStrut scrollers = container.GetScrollbarSizes();
-  NGBoxStrut borders_and_scrollers = borders + scrollers;
-  content_offset_ = NGLogicalOffset{borders_and_scrollers.inline_start,
-                                    borders_and_scrollers.block_start};
-
+  NGBoxStrut borders_and_scrollers =
+      ComputeBorders(container_space, container_style) +
+      container.GetScrollbarSizes();
   NGPhysicalBoxStrut physical_borders = borders_and_scrollers.ConvertToPhysical(
-      writing_mode, container_style_.Direction());
-  content_physical_offset_ =
-      NGPhysicalOffset(physical_borders.left, physical_borders.top);
-
-  container_size_ = container_builder_->Size();
-  container_size_.inline_size -= borders_and_scrollers.InlineSum();
-  container_size_.block_size -= borders_and_scrollers.BlockSum();
+      container_style.GetWritingMode(), container_style.Direction());
 
   icb_size_ = container_space.InitialContainingBlockSize();
+
+  default_containing_block_.style = &container_style;
+  default_containing_block_.content_size = container_builder_->Size();
+  default_containing_block_.content_size.inline_size -=
+      borders_and_scrollers.InlineSum();
+  default_containing_block_.content_size.block_size -=
+      borders_and_scrollers.BlockSum();
+
+  default_containing_block_.content_offset = NGLogicalOffset{
+      borders_and_scrollers.inline_start, borders_and_scrollers.block_start};
+  default_containing_block_.content_physical_offset =
+      NGPhysicalOffset(physical_borders.left, physical_borders.top);
 }
 
 void NGOutOfFlowLayoutPart::Run(bool update_legacy) {
@@ -83,8 +83,7 @@ NGOutOfFlowLayoutPart::GetContainingBlockInfo(
     DCHECK(containing_blocks_map_.Contains(descendant.inline_container));
     return containing_blocks_map_.at(descendant.inline_container);
   }
-  return ContainingBlockInfo{&container_style_, container_size_,
-                             content_offset_, content_physical_offset_};
+  return default_containing_block_;
 }
 
 void NGOutOfFlowLayoutPart::ComputeInlineContainingBlocks(
@@ -106,7 +105,7 @@ void NGOutOfFlowLayoutPart::ComputeInlineContainingBlocks(
       &inline_container_fragments, &container_builder_size);
   NGPhysicalSize container_builder_physical_size =
       container_builder_size.ConvertToPhysical(
-          container_style_.GetWritingMode());
+          default_containing_block_.style->GetWritingMode());
   // Translate start/end fragments into ContainingBlockInfo.
   for (auto& block_info : inline_container_fragments) {
     NGLogicalOffset inline_content_offset;
@@ -159,8 +158,10 @@ void NGOutOfFlowLayoutPart::ComputeInlineContainingBlocks(
     const NGPhysicalFragment* start_fragment = block_info.value.start_fragment;
     const NGPhysicalLineBoxFragment* start_linebox_fragment =
         block_info.value.start_linebox_fragment;
-    WritingMode container_writing_mode = container_style_.GetWritingMode();
-    TextDirection container_direction = container_style_.Direction();
+    WritingMode container_writing_mode =
+        default_containing_block_.style->GetWritingMode();
+    TextDirection container_direction =
+        default_containing_block_.style->Direction();
     // Step 1
     NGLogicalOffset start_fragment_logical_offset =
         block_info.value.start_fragment_offset.ConvertToLogical(
@@ -248,16 +249,14 @@ void NGOutOfFlowLayoutPart::ComputeInlineContainingBlocks(
     NGLogicalOffset default_container_offset;
     if (RuntimeEnabledFeatures::LayoutNGPaintFragmentsEnabled()) {
       // NGPaint offset is wrt parent fragment.
-      default_container_offset =
-          start_fragment_logical_offset - content_offset_;
-      default_container_offset += NGLogicalOffset(
-          inline_cb_borders.inline_start, inline_cb_borders.block_start);
+      default_container_offset = start_fragment_logical_offset -
+                                 default_containing_block_.content_offset;
     } else {
       // Legacy offset is wrt inline container.
       default_container_offset =
           NGLogicalOffset(inline_cb_borders.inline_start,
                           inline_cb_borders.block_start) -
-          content_offset_;
+          default_containing_block_.content_offset;
     }
 
     containing_blocks_map_.insert(
@@ -339,8 +338,11 @@ scoped_refptr<NGLayoutResult> NGOutOfFlowLayoutPart::LayoutDescendant(
   // to the padding box so add back the container's borders.
   NGBoxStrut inset = node_position.inset.ConvertToLogical(
       container_writing_mode, container_info.style->Direction());
-  offset->inline_offset = inset.inline_start + content_offset_.inline_offset;
-  offset->block_offset = inset.block_start + content_offset_.block_offset;
+  offset->inline_offset =
+      inset.inline_start +
+      default_containing_block_.content_offset.inline_offset;
+  offset->block_offset =
+      inset.block_start + default_containing_block_.content_offset.block_offset;
 
   offset->inline_offset +=
       container_info.default_container_offset.inline_offset;
@@ -374,7 +376,7 @@ scoped_refptr<NGLayoutResult> NGOutOfFlowLayoutPart::GenerateFragment(
   WritingMode writing_mode(descendant.Style().GetWritingMode());
   NGLogicalSize container_size(
       container_info.content_size
-          .ConvertToPhysical(container_style_.GetWritingMode())
+          .ConvertToPhysical(default_containing_block_.style->GetWritingMode())
           .ConvertToLogical(writing_mode));
 
   LayoutUnit inline_size =

third_party/WebKit/Source/core/layout/ng/ng_out_of_flow_layout_part.h

@@ -79,16 +79,11 @@ class CORE_EXPORT NGOutOfFlowLayoutPart {
       const Optional<LayoutUnit>& block_estimate,
       const NGAbsolutePhysicalPosition node_position);
 
-  const ComputedStyle& container_style_;
   NGFragmentBuilder* container_builder_;
-
   bool contains_absolute_;
   bool contains_fixed_;
-  ContainingBlockInfo default_containing_block_;
-  NGLogicalOffset content_offset_;
-  NGPhysicalOffset content_physical_offset_;
-  NGLogicalSize container_size_;
   NGPhysicalSize icb_size_;
+  ContainingBlockInfo default_containing_block_;
   HashMap<const LayoutObject*, ContainingBlockInfo> containing_blocks_map_;
 };