Make code compile with clang_use_chrome_plugin (part I)

This change contains files in core/fpdfapi directory. This is part
of the efforts to make PDFium code compilable by Clang chromium
style plugins.

The changes are mainly the following:
-- move inline constructor/destructor of complex class/struct out-of-line;
-- add constructor/destructor of complex class/struct if not
   explicitly defined;
-- add explicit out-of-line copy constructor when needed;
-- move inline virtual functions out-of-line;
-- Properly mark virtual functions with 'override';
-- some minor cleanups;

BUG=pdfium:469

Review-Url: https://codereview.chromium.org/2060973002

1 files changed, 1 insertions, 0 deletions

diff --git a/core/fpdfapi/fpdf_page/include/cpdf_pageobjectholder.h b/core/fpdfapi/fpdf_page/include/cpdf_pageobjectholder.h
index 7ac9f2cea0..e75604858a 100644
--- a/core/fpdfapi/fpdf_page/include/cpdf_pageobjectholder.h
+++ b/core/fpdfapi/fpdf_page/include/cpdf_pageobjectholder.h
@@ -24,6 +24,7 @@ class CPDF_ContentParser;
 class CPDF_PageObjectHolder {
  public:
   CPDF_PageObjectHolder();
+  virtual ~CPDF_PageObjectHolder();
 
   void ContinueParse(IFX_Pause* pPause);
   bool IsParsed() const { return m_ParseState == CONTENT_PARSED; }