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, 4 insertions, 2 deletions

diff --git a/xfa/fxfa/include/xfa_ffpageview.h b/xfa/fxfa/include/xfa_ffpageview.h
index ab98d54e62..2c703b0b00 100644
--- a/xfa/fxfa/include/xfa_ffpageview.h
+++ b/xfa/fxfa/include/xfa_ffpageview.h
@@ -58,14 +58,16 @@ class CXFA_FFPageWidgetIterator : public IXFA_WidgetIterator {
   CXFA_LayoutItemIterator m_sIterator;
 };
 typedef CFX_ArrayTemplate<CXFA_FFWidget*> CXFA_WidgetArray;
+
 class CXFA_TabParam {
  public:
-  CXFA_TabParam() : m_pWidget(NULL) {}
-  ~CXFA_TabParam() {}
+  CXFA_TabParam();
+  ~CXFA_TabParam();
 
   CXFA_FFWidget* m_pWidget;
   CXFA_WidgetArray m_Children;
 };
+
 class CXFA_FFTabOrderPageWidgetIterator : public IXFA_WidgetIterator {
  public:
   CXFA_FFTabOrderPageWidgetIterator(CXFA_FFPageView* pPageView,