Make code compile with clang_use_chrome_plugin (part V)

xfa/fxfa/include/xfa_ffapp.h

Index: xfa/fxfa/include/xfa_ffapp.h
diff --git a/xfa/fxfa/include/xfa_ffapp.h b/xfa/fxfa/include/xfa_ffapp.h
index 1e8bf5b117360e2cd7922050b8db52616ef8dbf7..5780859a92831fc84ef157e4a0c309010fd78479 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;