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, 6 insertions, 0 deletions

diff --git a/xfa/fxbarcode/oned/BC_OnedUPCAWriter.cpp b/xfa/fxbarcode/oned/BC_OnedUPCAWriter.cpp
index 580e1a8444..2b06c8519b 100644
--- a/xfa/fxbarcode/oned/BC_OnedUPCAWriter.cpp
+++ b/xfa/fxbarcode/oned/BC_OnedUPCAWriter.cpp
@@ -105,6 +105,12 @@ uint8_t* CBC_OnedUPCAWriter::Encode(const CFX_ByteString& contents,
   return ret;
 }
 
+uint8_t* CBC_OnedUPCAWriter::Encode(const CFX_ByteString& contents,
+                                    int32_t& outLength,
+                                    int32_t& e) {
+  return nullptr;
+}
+
 void CBC_OnedUPCAWriter::ShowChars(const CFX_WideStringC& contents,
                                    CFX_DIBitmap* pOutBitmap,
                                    CFX_RenderDevice* device,