[LayoutNG] Introduce NGPhysicalFragment and make NGFragment a 'view'

third_party/WebKit/Source/core/layout/ng/ng_block_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/ng_block_layout_algorithm.h"
 
 #include "core/layout/LayoutBox.h"
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_fragment_builder.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/layout/ng/ng_length_utils.h"
+#include "core/layout/ng/ng_units.h"
 #include "core/style/ComputedStyle.h"
 #include "platform/LengthFunctions.h"
 
 namespace blink {
 
 NGBlockLayoutAlgorithm::NGBlockLayoutAlgorithm(
     PassRefPtr<const ComputedStyle> style,
     NGBox* first_child)
     : style_(style), first_child_(first_child), state_(kStateInit) {}
 
 bool NGBlockLayoutAlgorithm::Layout(const NGConstraintSpace* constraint_space,
-                                    NGFragment** out) {
+                                    NGPhysicalFragment** out) {
   switch (state_) {
     case kStateInit: {
       LayoutUnit inline_size =
           computeInlineSizeForFragment(*constraint_space, *style_);
       // TODO(layout-ng): For quirks mode, should we pass blockSize instead of
       // -1?
       LayoutUnit block_size = computeBlockSizeForFragment(
           *constraint_space, *style_, LayoutUnit(-1));
       constraint_space_for_children_ = new NGConstraintSpace(
           *constraint_space, NGLogicalSize(inline_size, block_size));
       content_size_ = LayoutUnit();
 
-      builder_ = new NGFragmentBuilder(NGFragmentBase::FragmentBox);
+      builder_ = new NGFragmentBuilder(NGPhysicalFragmentBase::FragmentBox);
       builder_->SetInlineSize(inline_size).SetBlockSize(block_size);
       current_child_ = first_child_;
       state_ = kStateChildLayout;
       return false;
     }
     case kStateChildLayout: {
       if (current_child_) {
         NGFragment* fragment;
         if (!current_child_->Layout(constraint_space_for_children_, &fragment))
           return false;
         NGBoxStrut child_margins = computeMargins(
             *constraint_space_for_children_, *current_child_->Style());
         // TODO(layout-ng): Support auto margins
-        fragment->SetOffset(child_margins.inline_start,
-                            content_size_ + child_margins.block_start);
-        current_child_->PositionUpdated(*fragment);
+        builder_->AddChild(
+            fragment,
+            NGLogicalOffset(child_margins.inline_start,
+                            content_size_ + child_margins.block_start));
+
         content_size_ += fragment->BlockSize() + child_margins.BlockSum();
         max_inline_size_ =
             std::max(max_inline_size_,
                      fragment->InlineSize() + child_margins.InlineSum());
-        builder_->AddChild(fragment);
         current_child_ = current_child_->NextSibling();
         if (current_child_)
           return false;
       }
 
       state_ = kStateFinalize;
       return false;
     }
     case kStateFinalize: {
       // Recompute the block-axis size now that we know our content size.
       LayoutUnit block_size = computeBlockSizeForFragment(
           *constraint_space, *style_, content_size_);
 
       builder_->SetBlockSize(block_size)
           .SetInlineOverflow(max_inline_size_)
           .SetBlockOverflow(content_size_);
       *out = builder_->ToFragment();
       state_ = kStateInit;
       return true;
     }
   };
   NOTREACHED();
   *out = nullptr;
   return true;
 }
 
 }  // namespace blink