Make code compile with clang_use_chrome_plugin (part V)chromium/2770

This change mainly contains files in xfa/fxfa 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/2071683002

1 files changed, 2 insertions, 1 deletions

diff --git a/xfa/fxfa/parser/xfa_script_signaturepseudomodel.h b/xfa/fxfa/parser/xfa_script_signaturepseudomodel.h
index bba0fd5827..3339ff0852 100644
--- a/xfa/fxfa/parser/xfa_script_signaturepseudomodel.h
+++ b/xfa/fxfa/parser/xfa_script_signaturepseudomodel.h
@@ -13,7 +13,8 @@
 class CScript_SignaturePseudoModel : public CXFA_OrdinaryObject {
  public:
   CScript_SignaturePseudoModel(CXFA_Document* pDocument);
-  ~CScript_SignaturePseudoModel();
+  ~CScript_SignaturePseudoModel() override;
+
   void Script_SignaturePseudoModel_Verify(CFXJSE_Arguments* pArguments);
   void Script_SignaturePseudoModel_Sign(CFXJSE_Arguments* pArguments);
   void Script_SignaturePseudoModel_Enumerate(CFXJSE_Arguments* pArguments);