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, 5 insertions, 4 deletions

diff --git a/xfa/fxfa/include/xfa_ffapp.h b/xfa/fxfa/include/xfa_ffapp.h
index 1e8bf5b117..5780859a92 100644
--- a/xfa/fxfa/include/xfa_ffapp.h
+++ b/xfa/fxfa/include/xfa_ffapp.h
@@ -24,11 +24,12 @@ class IFWL_AdapterTimerMgr;
 class CXFA_FileRead : public IFX_FileRead {
  public:
   explicit CXFA_FileRead(const CFX_ArrayTemplate<CPDF_Stream*>& streams);
+  ~CXFA_FileRead() override;
 
-  virtual FX_FILESIZE GetSize();
-  virtual FX_BOOL ReadBlock(void* buffer, FX_FILESIZE offset, size_t size);
-
-  virtual void Release() { delete this; }
+  // IFX_FileRead
+  FX_FILESIZE GetSize() override;
+  FX_BOOL ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override;
+  void Release() override;
 
  protected:
   CFX_ObjectArray<CPDF_StreamAcc> m_Data;