Add ptr_util.h from base until std::make_unique<> available

fpdfsdk/pdfwindow/PWL_Wnd.cpp

 // 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
 
 #include <map>
 
 #include "fpdfsdk/pdfwindow/PWL_ScrollBar.h"
 #include "fpdfsdk/pdfwindow/PWL_Utils.h"
 #include "fpdfsdk/pdfwindow/PWL_Wnd.h"
+#include "third_party/base/ptr_util.h"
 
 static std::map<int32_t, CPWL_Timer*>& GetPWLTimeMap() {
   // Leak the object at shutdown.
   static auto timeMap = new std::map<int32_t, CPWL_Timer*>;
   return *timeMap;
 }
 
 PWL_CREATEPARAM::PWL_CREATEPARAM()
     : rcRectWnd(0, 0, 0, 0),
       pSystemHandler(nullptr),
@@ skipping 57 matching lines @@
   if (pTimer->m_pAttached)
     pTimer->m_pAttached->TimerProc();
 }
 
 CPWL_TimerHandler::CPWL_TimerHandler() {}
 
 CPWL_TimerHandler::~CPWL_TimerHandler() {}
 
 void CPWL_TimerHandler::BeginTimer(int32_t nElapse) {
   if (!m_pTimer)
-    m_pTimer = WrapUnique(new CPWL_Timer(this, GetSystemHandler()));
+    m_pTimer = pdfium::MakeUnique<CPWL_Timer>(this, GetSystemHandler());
 
-  if (m_pTimer)
-    m_pTimer->SetPWLTimer(nElapse);
+  m_pTimer->SetPWLTimer(nElapse);
 }
 
 void CPWL_TimerHandler::EndTimer() {
   if (m_pTimer)
     m_pTimer->KillPWLTimer();
 }
 
 void CPWL_TimerHandler::TimerProc() {}
 
 class CPWL_MsgControl {
@@ skipping 929 matching lines @@
   return FALSE;
 }
 
 FX_BOOL CPWL_Wnd::IsALTpressed(uint32_t nFlag) const {
   if (CFX_SystemHandler* pSystemHandler = GetSystemHandler()) {
     return pSystemHandler->IsALTKeyDown(nFlag);
   }
 
   return FALSE;
 }