Make code compile with clang_use_chrome_plugin (part I)

core/fpdfapi/fpdf_edit/cpdf_pagecontentgenerator.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/fpdf_edit/include/cpdf_pagecontentgenerator.h"
 
 #include "core/fpdfapi/fpdf_edit/include/cpdf_creator.h"
 #include "core/fpdfapi/fpdf_page/include/cpdf_image.h"
@@ skipping 13 matching lines @@
      << matrix.e << " " << matrix.f;
   return ar;
 }
 
 CPDF_PageContentGenerator::CPDF_PageContentGenerator(CPDF_Page* pPage)
     : m_pPage(pPage), m_pDocument(m_pPage->m_pDocument) {
   for (const auto& pObj : *pPage->GetPageObjectList())
     InsertPageObject(pObj.get());
 }
 
+CPDF_PageContentGenerator::~CPDF_PageContentGenerator() {}
+
 FX_BOOL CPDF_PageContentGenerator::InsertPageObject(
     CPDF_PageObject* pPageObject) {
   return pPageObject && m_pageObjects.Add(pPageObject);
 }
 
 void CPDF_PageContentGenerator::GenerateContent() {
   CFX_ByteTextBuf buf;
   CPDF_Dictionary* pPageDict = m_pPage->m_pFormDict;
   for (int i = 0; i < m_pageObjects.GetSize(); ++i) {
     CPDF_PageObject* pPageObj = m_pageObjects[i];
@@ skipping 115 matching lines @@
     CPDF_StreamAcc contentStream;
     contentStream.LoadAllData(pStream);
     ProcessForm(buf, contentStream.GetData(), contentStream.GetSize(), matrix);
   }
   CPDF_Stream* pStream = new CPDF_Stream(nullptr, 0, nullptr);
   pStream->SetData(buf.GetBuffer(), buf.GetLength(), FALSE, FALSE);
   m_pDocument->AddIndirectObject(pStream);
   m_pPage->m_pFormDict->SetAtReference("Contents", m_pDocument,
                                        pStream->GetObjNum());
 }