Top down version of algorithm to position margins and floats in LayoutNG

third_party/WebKit/Source/core/layout/ng/ng_floating_object.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 NGFloatingObject_h
 #define NGFloatingObject_h
 
 #include "core/layout/ng/ng_block_node.h"
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_units.h"
 #include "core/style/ComputedStyle.h"
 #include "core/style/ComputedStyleConstants.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class NGPhysicalFragment;
 
 // Struct that keeps all information needed to position floats in LayoutNG.
 struct CORE_EXPORT NGFloatingObject
     : public GarbageCollected<NGFloatingObject> {
   NGFloatingObject(NGPhysicalFragment* fragment,
-                   const NGConstraintSpace* space,
+                   NGConstraintSpace* space,
                    NGBlockNode* node,
                    const ComputedStyle& style,
                    const NGBoxStrut& margins)
       : fragment(fragment), space(space), node(node), margins(margins) {
     exclusion_type = NGExclusion::kFloatLeft;
     if (style.floating() == EFloat::kRight)
       exclusion_type = NGExclusion::kFloatRight;
     clear_type = style.clear();
   }
 
   Member<NGPhysicalFragment> fragment;
-  Member<const NGConstraintSpace> space;
+  // TODO(glebl): Constraint space should be const here.
+  Member<NGConstraintSpace> space;
   Member<NGBlockNode> node;
   NGExclusion::Type exclusion_type;
   EClear clear_type;
   NGBoxStrut margins;
 
   DEFINE_INLINE_TRACE() {
     visitor->trace(fragment);
     visitor->trace(space);
     visitor->trace(node);
   }
 };
 
 }  // namespace blink
 
 #endif  // NGFloatingObject_h