Add container_block_offset,top_offset to NGFloatingObject.

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

 // Copyright 2017 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_floats_utils.h"
 
 #include "core/layout/ng/ng_box_fragment.h"
 #include "core/layout/ng/ng_layout_opportunity_iterator.h"
 
 namespace blink {
@@ skipping 60 matching lines @@
   exclusion.type = exclusion_type;
   NGLogicalRect& rect = exclusion.rect;
   rect.offset = opportunity.offset;
   rect.offset.inline_offset += float_offset;
 
   rect.size.inline_size = fragment.InlineSize() + margins.InlineSum();
   rect.size.block_size = fragment.BlockSize() + margins.BlockSum();
   return exclusion;
 }
 
-// Calculates the Floating Object's left offset from the provided parent_space
-// and {@code floating_object}'s space and margins.
-LayoutUnit CalculateLeftOffset(const NGConstraintSpace& new_parent_space,
-                               const NGLogicalOffset& float_logical_offset,
-                               const NGFloatingObject& floating_object) {
+// Updates the Floating Object's left and top offsets.
+NGPhysicalOffset CalculateFloatingObjectPaintOffset(
+    const NGConstraintSpace& new_parent_space,
+    const NGLogicalOffset& float_logical_offset,
+    const NGFloatingObject& floating_object) {
   // TODO(glebl): We should use physical offset here.
-  return floating_object.from_offset.inline_offset -
-         new_parent_space.BfcOffset().inline_offset +
-         float_logical_offset.inline_offset;
+  LayoutUnit left_offset = floating_object.from_offset.inline_offset -
+                           new_parent_space.BfcOffset().inline_offset +
+                           float_logical_offset.inline_offset;
+  DCHECK(floating_object.parent_bfc_block_offset);
+  LayoutUnit top_offset = floating_object.from_offset.block_offset -
+                          floating_object.parent_bfc_block_offset.value() +
+                          float_logical_offset.block_offset;
+  return {left_offset, top_offset};
 }
 }  // namespace
 
 NGPositionedFloat PositionFloat(NGFloatingObject* floating_object,
                                 NGConstraintSpace* new_parent_space) {
   DCHECK(floating_object);
   DCHECK(floating_object->fragment) << "Fragment cannot be null here";
 
   // TODO(ikilpatrick): The writing mode switching here looks wrong.
   NGBoxFragment float_fragment(
@@ skipping 24 matching lines @@
   }
 
   // Add the float as an exclusion.
   const NGExclusion exclusion = CreateExclusion(
       float_fragment, opportunity, float_offset, floating_object->margins,
       floating_object->exclusion_type);
   new_parent_space->AddExclusion(exclusion);
 
   NGLogicalOffset logical_offset = CalculateLogicalOffsetForOpportunity(
       opportunity, float_offset, floating_object);
-
-  LayoutUnit left_offset =
-      CalculateLeftOffset(*new_parent_space, logical_offset, *floating_object);
+  NGPhysicalOffset paint_offset = CalculateFloatingObjectPaintOffset(
+      *new_parent_space, logical_offset, *floating_object);
 
   return NGPositionedFloat(floating_object->fragment, logical_offset,
-                           left_offset);
+                           paint_offset);
 }
 
 const Vector<NGPositionedFloat> PositionFloats(
     LayoutUnit origin_block_offset,
     LayoutUnit from_block_offset,
+    LayoutUnit parent_bfc_offset,
     const Vector<RefPtr<NGFloatingObject>>& floating_objects,
     NGConstraintSpace* space) {
   Vector<NGPositionedFloat> positioned_floats;
   positioned_floats.ReserveCapacity(floating_objects.size());
 
   for (auto& floating_object : floating_objects) {
     floating_object->origin_offset.block_offset = origin_block_offset;
     floating_object->from_offset.block_offset = from_block_offset;
+    floating_object->parent_bfc_block_offset = parent_bfc_offset;
     positioned_floats.push_back(PositionFloat(floating_object.Get(), space));
   }
 
   return positioned_floats;
 }
 
 }  // namespace blink