Use override in more classes in fpdfsdk/

fpdfsdk/include/fsdk_baseform.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_FSDK_BASEFORM_H_
 #define FPDFSDK_INCLUDE_FSDK_BASEFORM_H_
 
 #if _FX_OS_ == _FX_ANDROID_
@@ skipping 38 matching lines @@
   CFX_WideString sChange;    // in[out]
   CFX_WideString sChangeEx;  // in
   FX_BOOL bKeyDown;          // in
   int nSelEnd;               // in[out]
   int nSelStart;             // in[out]
   CFX_WideString sValue;     // in[out]
   FX_BOOL bWillCommit;       // in
   FX_BOOL bFieldFull;        // in
   FX_BOOL bRC;               // in[out]
 } PDFSDK_FieldAction;
+
 class CPDFSDK_Widget : public CPDFSDK_Annot {
  public:
   CPDFSDK_Widget(CPDF_Annot* pAnnot,
                  CPDFSDK_PageView* pPageView,
                  CPDFSDK_InterForm* pInterForm);
-  virtual ~CPDFSDK_Widget();
+  ~CPDFSDK_Widget() override;
 
-  virtual CFX_ByteString GetSubType() const;
+  // CPDFSDK_Annot
+  CFX_ByteString GetSubType() const override;
+  CPDF_Action GetAAction(CPDF_AAction::AActionType eAAT) override;
 
-  virtual CPDF_Action GetAAction(CPDF_AAction::AActionType eAAT);
+  int GetLayoutOrder() const override { return 2; }
 
+  // Possible values from PDF 32000-1:2008, table 221.
+  // FIELDFLAG_READONLY
+  // FIELDFLAG_REQUIRED
+  // FIELDFLAG_NOEXPORT
   int GetFieldType() const;
-  // define layout order to 2.
-  virtual int GetLayoutOrder() const { return 2; }
-  /*
-  FIELDFLAG_READONLY
-  FIELDFLAG_REQUIRED
-  FIELDFLAG_NOEXPORT
-  */
 
   int GetFieldFlags() const;
   int GetRotate() const;
 
   FX_BOOL GetFillColor(FX_COLORREF& color) const;
   FX_BOOL GetBorderColor(FX_COLORREF& color) const;
   FX_BOOL GetTextColor(FX_COLORREF& color) const;
   FX_FLOAT GetFontSize() const;
 
   int GetSelectedIndex(int nIndex) const;
@@ skipping 211 matching lines @@
   static CPDF_Rect GetAnnotRect(CPDFSDK_Annot* pAnnot);
 
   CPDFSDK_PageView* m_pPageView;
   CFX_ByteString m_sType;
   CFX_ByteString m_sSubType;
   int m_nTabs;
   CPDFSDK_Annots m_Annots;
 };
 
 #endif  // FPDFSDK_INCLUDE_FSDK_BASEFORM_H_