Use override in more classes in fpdfsdk/

fpdfsdk/include/javascript/JS_Runtime.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_JS_RUNTIME_H_
 #define FPDFSDK_INCLUDE_JAVASCRIPT_JS_RUNTIME_H_
 
 #include "../../../third_party/base/nonstd_unique_ptr.h"
@@ skipping 13 matching lines @@
 class CJS_FieldEvent {
  public:
   CFX_WideString sTargetName;
   JS_EVENT_T eEventType;
   CJS_FieldEvent* pNext;
 };
 
 class CJS_Runtime : public IFXJS_Runtime {
  public:
   CJS_Runtime(CPDFDoc_Environment* pApp);
-  virtual ~CJS_Runtime();
+  ~CJS_Runtime() override;
 
-  virtual IFXJS_Context* NewContext();
-  virtual void ReleaseContext(IFXJS_Context* pContext);
-  virtual IFXJS_Context* GetCurrentContext();
-
-  virtual void SetReaderDocument(CPDFSDK_Document* pReaderDoc);
-  virtual CPDFSDK_Document* GetReaderDocument() { return m_pDocument; }
+  // IFXJS_Runtime
+  IFXJS_Context* NewContext() override;
+  void ReleaseContext(IFXJS_Context* pContext) override;
+  IFXJS_Context* GetCurrentContext() override;
+  void SetReaderDocument(CPDFSDK_Document* pReaderDoc) override;
+  CPDFSDK_Document* GetReaderDocument() override { return m_pDocument; }
 
   CPDFDoc_Environment* GetReaderApp() { return m_pApp; }
 
   FX_BOOL InitJSObjects();
 
   FX_BOOL AddEventToLoop(const CFX_WideString& sTargetName,
                          JS_EVENT_T eEventType);
   void RemoveEventInLoop(const CFX_WideString& sTargetName,
                          JS_EVENT_T eEventType);
   void RemoveEventsInLoop(CJS_FieldEvent* pStart);
@@ skipping 15 matching lines @@
   FX_BOOL m_bBlocking;
   CJS_FieldEvent* m_pFieldEventPath;
 
   v8::Isolate* m_isolate;
   bool m_isolateManaged;
   nonstd::unique_ptr<CJS_ArrayBufferAllocator> m_pArrayBufferAllocator;
   v8::Global<v8::Context> m_context;
 };
 
 #endif  // FPDFSDK_INCLUDE_JAVASCRIPT_JS_RUNTIME_H_