Make NGFragment to own NGPhysicalFragment

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

Index: third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h b/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
index f6a9c5370053fb1ca0b76cd8a1662b8978117369..ccb3d0835cc9575ef6091c6a295d018410a21662 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_layout_algorithm.h
@@ -33,7 +33,7 @@ class CORE_EXPORT NGLayoutAlgorithm
   // returns true. The same constraint space has to be passed each time.
   // TODO(layout-ng): Should we have a StartLayout function to avoid passing
   // the same space for each Layout iteration?
-  virtual bool Layout(const NGConstraintSpace*, NGPhysicalFragment**) = 0;
+  virtual bool Layout(const NGConstraintSpace&, NGPhysicalFragment**) = 0;
 
   DEFINE_INLINE_VIRTUAL_TRACE() {}
 };