Use smart pointers for class owned pointers

fpdfsdk/pdfwindow/PWL_Wnd.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef FPDFSDK_PDFWINDOW_PWL_WND_H_
 #define FPDFSDK_PDFWINDOW_PWL_WND_H_
 
+#include <memory>
 #include <vector>
 
 #include "core/fpdfdoc/include/cpdf_formcontrol.h"
 #include "core/fxcrt/include/fx_basic.h"
 #include "fpdfsdk/cfx_systemhandler.h"
 
 class CPWL_MsgControl;
 class CPWL_ScrollBar;
 class CPWL_Timer;
 class CPWL_TimerHandler;
@@ skipping 211 matching lines @@
  public:
   CPWL_TimerHandler();
   virtual ~CPWL_TimerHandler();
 
   void BeginTimer(int32_t nElapse);
   void EndTimer();
   virtual void TimerProc();
   virtual CFX_SystemHandler* GetSystemHandler() const = 0;
 
  private:
-  CPWL_Timer* m_pTimer;
+  std::unique_ptr<CPWL_Timer> m_pTimer;
 };
 
 class CPWL_Wnd : public CPWL_TimerHandler {
   friend class CPWL_MsgControl;
 
  public:
   CPWL_Wnd();
   ~CPWL_Wnd() override;
 
   void Create(const PWL_CREATEPARAM& cp);
@@ skipping 170 matching lines @@
   CFX_FloatRect m_rcWindow;
   CFX_FloatRect m_rcClip;
 
   FX_BOOL m_bCreated;
   FX_BOOL m_bVisible;
   FX_BOOL m_bNotifying;
   FX_BOOL m_bEnabled;
 };
 
 #endif  // FPDFSDK_PDFWINDOW_PWL_WND_H_