Make FPDF_Document always be CPDF_Document.

Greatly minimize the impact between going back and forth from
XFA being on/off, so that XFA case is just an extension beyond
the non-XFA data structures we've shipped for years, instead of
being a complete replacement of them.

Change-Id: I6c98206e0ec99ea443547a4931eba912b1764d54
Reviewed-on: https://pdfium-review.googlesource.com/31690
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index adf4eca75d..4466df640e 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -42,7 +42,10 @@ class JBig2_DocumentContext;
 class CPDF_Document : public CPDF_IndirectObjectHolder {
  public:
   // Type from which the XFA extension can subclass itself.
-  class Extension {};
+  class Extension {
+   public:
+    virtual ~Extension() {}
+  };
 
   explicit CPDF_Document(std::unique_ptr<CPDF_Parser> pParser);
   ~CPDF_Document() override;