Fix stack-use-after-return in ~ScopeRecorder

Source/core/paint/ScopeRecorder.h

 // Copyright 2015 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 ScopeRecorder_h
 #define ScopeRecorder_h
 
 #include "core/CoreExport.h"
 #include "platform/graphics/paint/DisplayItem.h"
 
 namespace blink {
 
 class DisplayItemList;
 class GraphicsContext;
 class LayoutObject;
 
 class CORE_EXPORT ScopeRecorder {
 public:
     ScopeRecorder(GraphicsContext&, const DisplayItemClientWrapper&);
 
     ~ScopeRecorder();
 
 private:
     DisplayItemList* m_displayItemList;
-    const DisplayItemClientWrapper& m_object;
+    DisplayItemClientWrapper m_object;
 };
 
 } // namespace blink
 
 #endif // ScopeRecorder_h