Use std::unique_ptr to signal ownership transfer in WebCompositorSupport

third_party/WebKit/Source/platform/exported/WebScrollbarImpl.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 12 matching lines @@
  */
 
 #ifndef WebScrollbarImpl_h
 #define WebScrollbarImpl_h
 
 #include "platform/PlatformExport.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebScrollbar.h"
 #include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
+#include "wtf/PtrUtil.h"
+
+#include <memory>
 
 namespace blink {
 
 class Scrollbar;
 class PLATFORM_EXPORT WebScrollbarImpl final : public WebScrollbar {
   USING_FAST_MALLOC(WebScrollbarImpl);
   WTF_MAKE_NONCOPYABLE(WebScrollbarImpl);
 
  public:
-  static WebScrollbarImpl* create(Scrollbar* scrollbar) {
-    return new WebScrollbarImpl(scrollbar);
+  static std::unique_ptr<WebScrollbarImpl> create(Scrollbar* scrollbar) {
+    return wrapUnique(new WebScrollbarImpl(scrollbar));
   }
 
   // Implement WebScrollbar methods
   bool isOverlay() const override;
   int value() const override;
   WebPoint location() const override;
   WebSize size() const override;
   bool enabled() const override;
   int maximum() const override;
   int totalSize() const override;
@@ skipping 11 matching lines @@
 
  private:
   explicit WebScrollbarImpl(Scrollbar*);
 
   Persistent<Scrollbar> m_scrollbar;
 };
 
 }  // namespace blink
 
 #endif