Avoid the ptr.reset(new XXX()) anti-pattern

xfa/fwl/cfwl_datetimepicker.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 "xfa/fwl/cfwl_datetimepicker.h"
 
 #include <memory>
 #include <utility>
@@ skipping 35 matching lines @@
       new CFWL_MonthCalendar(m_pOwnerApp, std::move(monthProp), this));
 
   CFX_RectF rtMonthCal = m_pMonthCal->GetAutosizedWidgetRect();
   rtMonthCal.Set(0, 0, rtMonthCal.width, rtMonthCal.height);
   m_pMonthCal->SetWidgetRect(rtMonthCal);
 
   auto editProp = pdfium::MakeUnique<CFWL_WidgetProperties>();
   editProp->m_pParent = this;
   editProp->m_pThemeProvider = m_pProperties->m_pThemeProvider;
 
-  m_pEdit.reset(new CFWL_DateTimeEdit(m_pOwnerApp, std::move(editProp), this));
+  m_pEdit = pdfium::MakeUnique<CFWL_DateTimeEdit>(m_pOwnerApp,
+                                                  std::move(editProp), this);
   RegisterEventTarget(m_pMonthCal.get());
   RegisterEventTarget(m_pEdit.get());
 }
 
 CFWL_DateTimePicker::~CFWL_DateTimePicker() {
   UnregisterEventTarget();
 }
 
 FWL_Type CFWL_DateTimePicker::GetClassID() const {
   return FWL_Type::DateTimePicker;
@@ skipping 549 matching lines @@
     if (DisForm_IsMonthCalendarVisible())
       ShowMonthCalendar(false);
     if (m_pEdit->GetStates() & FWL_WGTSTATE_Focused) {
       pMsg->m_pSrcTarget = m_pEdit.get();
       m_pEdit->GetDelegate()->OnProcessMessage(pMsg);
     }
   }
   rtInvalidate.Inflate(2, 2);
   RepaintRect(rtInvalidate);
 }