Use override in more classes in fpdfsdk/

fpdfsdk/include/fsdk_mgr.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_MGR_H_
 #define FPDFSDK_INCLUDE_FSDK_MGR_H_
 
 #include <map>
@@ skipping 339 matching lines @@
   FX_BOOL m_bOnWidget;
   FX_BOOL m_bValid;
   FX_BOOL m_bLocked;
   FX_BOOL m_bTakeOverPage;
 };
 
 template <class TYPE>
 class CGW_ArrayTemplate : public CFX_ArrayTemplate<TYPE> {
  public:
   CGW_ArrayTemplate() {}
-  virtual ~CGW_ArrayTemplate() {}
+  ~CGW_ArrayTemplate() {}
 
   typedef int (*LP_COMPARE)(TYPE p1, TYPE p2);
 
   void Sort(LP_COMPARE pCompare, FX_BOOL bAscent = TRUE) {
     int nSize = this->GetSize();
     QuickSort(0, nSize - 1, bAscent, pCompare);
   }
 
  private:
   void QuickSort(FX_UINT nStartPos,
@@ skipping 49 matching lines @@
     }
 
     if (nStartPos < m)
       QuickSort(nStartPos, m, bAscend, pCompare);
     if (nStopPos > m)
       QuickSort(m, nStopPos, bAscend, pCompare);
   }
 };
 
 #endif  // FPDFSDK_INCLUDE_FSDK_MGR_H_