Make code compile with clang_use_chrome_plugin (part III)

This change contains files in xfa/fxbarcode 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/2067903002

1 files changed, 7 insertions, 3 deletions

diff --git a/xfa/fxbarcode/datamatrix/BC_C40Encoder.h b/xfa/fxbarcode/datamatrix/BC_C40Encoder.h
index 9dcb1e5c5f..9737981f75 100644
--- a/xfa/fxbarcode/datamatrix/BC_C40Encoder.h
+++ b/xfa/fxbarcode/datamatrix/BC_C40Encoder.h
@@ -12,11 +12,15 @@
 class CBC_C40Encoder : public CBC_Encoder {
  public:
   CBC_C40Encoder();
-  virtual ~CBC_C40Encoder();
-  virtual int32_t getEncodingMode();
-  virtual void Encode(CBC_EncoderContext& context, int32_t& e);
+  ~CBC_C40Encoder() override;
+
+  // CBC_Encoder
+  int32_t getEncodingMode() override;
+  void Encode(CBC_EncoderContext& context, int32_t& e) override;
+
   static void writeNextTriplet(CBC_EncoderContext& context,
                                CFX_WideString& buffer);
+
   virtual void handleEOD(CBC_EncoderContext& context,
                          CFX_WideString& buffer,
                          int32_t& e);