Move ByteStringPool from document to indirect object holder.

core/fpdfapi/parser/cpdf_indirect_object_holder.cpp

 // Copyright 2016 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 "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
 
 #include "core/fpdfapi/parser/cpdf_object.h"
 #include "core/fpdfapi/parser/cpdf_parser.h"
 
-CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder() : m_LastObjNum(0) {}
+CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder()
+    : m_LastObjNum(0),
+      m_pByteStringPool(pdfium::MakeUnique<CFX_ByteStringPool>()) {}
 
-CPDF_IndirectObjectHolder::~CPDF_IndirectObjectHolder() {}
+CPDF_IndirectObjectHolder::~CPDF_IndirectObjectHolder() {
+  m_pByteStringPool.DeleteObject();  // Make weak.
+}
 
 CPDF_Object* CPDF_IndirectObjectHolder::GetIndirectObject(
     uint32_t objnum) const {
   auto it = m_IndirectObjs.find(objnum);
   return it != m_IndirectObjs.end() ? it->second.get() : nullptr;
 }
 
 CPDF_Object* CPDF_IndirectObjectHolder::GetOrParseIndirectObject(
     uint32_t objnum) {
   if (objnum == 0)
@@ skipping 45 matching lines @@
   return true;
 }
 
 void CPDF_IndirectObjectHolder::DeleteIndirectObject(uint32_t objnum) {
   CPDF_Object* pObj = GetIndirectObject(objnum);
   if (!pObj || pObj->GetObjNum() == CPDF_Object::kInvalidObjNum)
     return;
 
   m_IndirectObjs.erase(objnum);
 }