Use smart pointers for class owned pointers under xfa/fde

xfa/fde/cfde_txtedtbuf.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/fde/cfde_txtedtbuf.h"
 
 #include "xfa/fgas/crt/fgas_memory.h"
 
 namespace {
 
 const int kDefaultChunkSize = 1024;
 const int kDefaultChunkCount = 2;
 
 }  // namespace
 
 CFDE_TxtEdtBuf::CFDE_TxtEdtBuf()
-    : m_nChunkSize(kDefaultChunkSize),
-      m_nTotal(0),
-      m_bChanged(FALSE),
-      m_pAllocator(nullptr) {
-  ASSERT(m_nChunkSize);
+    : m_nChunkSize(kDefaultChunkSize), m_nTotal(0), m_bChanged(FALSE) {
   ResetChunkBuffer(kDefaultChunkCount, m_nChunkSize);
 }
 
 CFDE_TxtEdtBuf::~CFDE_TxtEdtBuf() {
   Clear(TRUE);
-  delete m_pAllocator;
   m_Chunks.RemoveAll();
 }
 
 int32_t CFDE_TxtEdtBuf::GetChunkSize() const {
   return m_nChunkSize;
 }
 
 int32_t CFDE_TxtEdtBuf::GetTextLength() const {
   return m_nTotal;
 }
@@ skipping 224 matching lines @@
       return FALSE;
   }
   m_bChanged = FALSE;
   return TRUE;
 }
 
 void CFDE_TxtEdtBuf::ResetChunkBuffer(int32_t nDefChunkCount,
                                       int32_t nChunkSize) {
   ASSERT(nChunkSize);
   ASSERT(nDefChunkCount);
-  delete m_pAllocator;
-  m_pAllocator = nullptr;
   m_Chunks.RemoveAll();
   m_nChunkSize = nChunkSize;
   int32_t nChunkLength =
       sizeof(FDE_CHUNKHEADER) + (m_nChunkSize - 1) * sizeof(FX_WCHAR);
   m_pAllocator = IFX_MemoryAllocator::Create(FX_ALLOCTYPE_Fixed, nDefChunkCount,
                                              nChunkLength);
   FDE_CHUNKHEADER* lpChunkHeader =
       static_cast<FDE_CHUNKHEADER*>(m_pAllocator->Alloc(nChunkLength));
   ASSERT(lpChunkHeader);
   lpChunkHeader->nUsed = 0;
@@ skipping 22 matching lines @@
   int32_t nCount = m_Chunks.GetSize();
   for (; i < nCount; i++) {
     nTotal += m_Chunks[i]->nUsed;
     if (nTotal > nIndex) {
       break;
     }
   }
   cp.nChunkIndex = i;
   cp.nCharIndex = m_Chunks[i]->nUsed - (nTotal - nIndex);
 }