[LayoutNG] Convert physical fragments to being RefCounted.

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

Index: third_party/WebKit/Source/core/layout/ng/ng_line_builder.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_line_builder.h b/third_party/WebKit/Source/core/layout/ng/ng_line_builder.h
index 702f220fa18bc9c655bd0d8fef8d5395d159266f..552a19bdbcfb90951465c201de8975eeba1ac811 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_line_builder.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_line_builder.h
@@ -6,6 +6,7 @@
 #define NGLineBuilder_h
 
 #include "core/CoreExport.h"
+#include "core/layout/ng/ng_physical_fragment.h"
 #include "core/layout/ng/ng_units.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Vector.h"
@@ -13,7 +14,6 @@
 namespace blink {
 
 class NGConstraintSpace;
-class NGFragment;
 class NGFragmentBuilder;
 class NGInlineNode;
 
@@ -61,7 +61,7 @@ class CORE_EXPORT NGLineBuilder final
 
   Member<NGInlineNode> inline_box_;
   Member<const NGConstraintSpace> constraint_space_;
-  HeapVector<Member<NGFragment>, 32> fragments_;
+  Vector<RefPtr<NGPhysicalFragment>, 32> fragments_;
   Vector<NGLogicalOffset, 32> offsets_;
   Vector<LineItemChunk, 32> line_item_chunks_;
   Vector<LineBoxData, 32> line_box_data_list_;