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, 0 deletions

diff --git a/xfa/fxfa/fm2js/xfa_fmparse.cpp b/xfa/fxfa/fm2js/xfa_fmparse.cpp
index 5fd6c06613..ebe68b9408 100644
--- a/xfa/fxfa/fm2js/xfa_fmparse.cpp
+++ b/xfa/fxfa/fm2js/xfa_fmparse.cpp
@@ -10,6 +10,8 @@
 
 CXFA_FMParse::CXFA_FMParse() : m_pToken(nullptr), m_pErrorInfo(0) {}
 
+CXFA_FMParse::~CXFA_FMParse() {}
+
 int32_t CXFA_FMParse::Init(const CFX_WideStringC& wsFormcalc,
                            CXFA_FMErrorInfo* pErrorInfo) {
   m_pErrorInfo = pErrorInfo;