Make NGFragment to own NGPhysicalFragment

third_party/WebKit/Source/core/layout/ng/ng_physical_text_fragment.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 NGPhysicalTextFragment_h
 #define NGPhysicalTextFragment_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_physical_fragment_base.h"
 #include "core/layout/ng/ng_layout_input_text.h"
 #include "platform/LayoutUnit.h"
 #include "platform/heap/Handle.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CORE_EXPORT NGPhysicalTextFragment final : public NGPhysicalFragmentBase {
  public:
   NGPhysicalTextFragment(NGPhysicalSize size, NGPhysicalSize overflow)
       : NGPhysicalFragmentBase(size, overflow, FragmentText, {}) {}
 
   String Text() const { return text_list_->Text(start_offset_, end_offset_); }
 
-  DEFINE_INLINE_TRACE_AFTER_DISPATCH() {
-    visitor->trace(text_list_);
-    NGPhysicalFragmentBase::traceAfterDispatch(visitor);
-  }
-
  private:
-  Member<NGLayoutInputText> text_list_;
+  std::unique_ptr<NGLayoutInputText> text_list_;
   unsigned start_offset_;
   unsigned end_offset_;
 };
 
 DEFINE_TYPE_CASTS(NGPhysicalTextFragment,
                   NGPhysicalFragmentBase,
                   text,
                   text->Type() == NGPhysicalFragmentBase::FragmentText,
                   text.Type() == NGPhysicalFragmentBase::FragmentText);
 
 }  // namespace blink
 
 #endif  // NGPhysicalTextFragment_h