Make NGFragment to own NGPhysicalFragment

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

 // 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.
 
 #include "core/layout/ng/ng_fragment_builder.h"
 
 namespace blink {
 
 NGFragmentBuilder::NGFragmentBuilder(
     NGPhysicalFragmentBase::NGFragmentType type)
@@ skipping 54 matching lines @@
   margin_strut_.negative_margin_block_end = from.negative_margin_block_end;
   return *this;
 }
 
 NGPhysicalFragment* NGFragmentBuilder::ToFragment() {
   // TODO(layout-ng): Support text fragments
   DCHECK_EQ(type_, NGPhysicalFragmentBase::FragmentBox);
   DCHECK_EQ(offsets_.size(), children_.size());
 
   NGPhysicalSize physical_size = size_.ConvertToPhysical(writing_mode_);
-  HeapVector<Member<const NGPhysicalFragmentBase>> children;
+  Vector<const NGPhysicalFragmentBase*> children;
   children.reserveCapacity(children_.size());
 
   for (size_t i = 0; i < children_.size(); ++i) {
-    NGPhysicalFragmentBase* child = children_[i].get();
+    NGPhysicalFragmentBase* child = children_[i];
     child->SetOffset(offsets_[i].ConvertToPhysical(
         writing_mode_, direction_, physical_size, child->Size()));
     children.append(child);
   }
   return new NGPhysicalFragment(physical_size,
                                 overflow_.ConvertToPhysical(writing_mode_),
                                 children, margin_strut_);
 }
 
 }  // namespace blink