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, 10 insertions, 8 deletions

diff --git a/xfa/fxfa/app/xfa_ffimage.h b/xfa/fxfa/app/xfa_ffimage.h
index 7bbeafc1ac..8771bde2fd 100644
--- a/xfa/fxfa/app/xfa_ffimage.h
+++ b/xfa/fxfa/app/xfa_ffimage.h
@@ -12,14 +12,16 @@
 class CXFA_FFImage : public CXFA_FFDraw {
  public:
   CXFA_FFImage(CXFA_FFPageView* pPageView, CXFA_WidgetAcc* pDataAcc);
-  virtual ~CXFA_FFImage();
-  virtual void RenderWidget(CFX_Graphics* pGS,
-                            CFX_Matrix* pMatrix = NULL,
-                            uint32_t dwStatus = 0,
-                            int32_t iRotate = 0);
-  virtual FX_BOOL IsLoaded();
-  virtual FX_BOOL LoadWidget();
-  virtual void UnloadWidget();
+  ~CXFA_FFImage() override;
+
+  // CXFA_FFWidget
+  void RenderWidget(CFX_Graphics* pGS,
+                    CFX_Matrix* pMatrix = NULL,
+                    uint32_t dwStatus = 0,
+                    int32_t iRotate = 0) override;
+  FX_BOOL IsLoaded() override;
+  FX_BOOL LoadWidget() override;
+  void UnloadWidget() override;
 };
 
 #endif  // XFA_FXFA_APP_XFA_FFIMAGE_H_