Use override in more classes in fpdfsdk/

fpdfsdk/include/javascript/global.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef FPDFSDK_INCLUDE_JAVASCRIPT_GLOBAL_H_
 #define FPDFSDK_INCLUDE_JAVASCRIPT_GLOBAL_H_
 
 #include "JS_Define.h"
@@ skipping 18 matching lines @@
   bool bData;
   CFX_ByteString sData;
   v8::Global<v8::Object> pData;
   bool bPersistent;
   bool bDeleted;
 };
 
 class global_alternate : public CJS_EmbedObj {
  public:
   global_alternate(CJS_Object* pJSObject);
-  virtual ~global_alternate();
+  ~global_alternate() override;
 
  public:
   FX_BOOL setPersistent(IFXJS_Context* cc,
                         const CJS_Parameters& params,
                         CJS_Value& vRet,
                         CFX_WideString& sError);
 
  public:
   FX_BOOL QueryProperty(const FX_WCHAR* propname);
   FX_BOOL DoProperty(IFXJS_Context* cc,
@@ skipping 24 matching lines @@
 
  private:
   CFX_MapByteStringToPtr m_mapGlobal;
   CFX_WideString m_sFilePath;
   CJS_GlobalData* m_pGlobalData;
   CPDFDoc_Environment* m_pApp;
 };
 
 class CJS_Global : public CJS_Object {
  public:
-  CJS_Global(JSFXObject pObject) : CJS_Object(pObject){};
-  virtual ~CJS_Global(void){};
+  explicit CJS_Global(JSFXObject pObject) : CJS_Object(pObject) {}
+  ~CJS_Global() override {}
 
-  virtual FX_BOOL InitInstance(IFXJS_Context* cc);
+  // CJS_Object
+  FX_BOOL InitInstance(IFXJS_Context* cc) override;
 
   DECLARE_SPECIAL_JS_CLASS(CJS_Global);
 
   JS_SPECIAL_STATIC_METHOD(setPersistent, global_alternate, global);
 };
 
 #endif  // FPDFSDK_INCLUDE_JAVASCRIPT_GLOBAL_H_