Use override in more classes in core/

core/src/fxge/skia/fx_skia_device.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.
 
 #ifndef CORE_SRC_FXGE_SKIA_FX_SKIA_DEVICE_H_
 #define CORE_SRC_FXGE_SKIA_FX_SKIA_DEVICE_H_
 
 #if defined(_SKIA_SUPPORT_)
 class CFX_SkiaDeviceDriver : public IFX_RenderDeviceDriver {
  public:
   CFX_SkiaDeviceDriver(CFX_DIBitmap* pBitmap,
                        int dither_bits,
                        FX_BOOL bRgbByteOrder,
                        CFX_DIBitmap* pOriDevice,
                        FX_BOOL bGroupKnockout);
-  virtual ~CFX_SkiaDeviceDriver();
+  ~CFX_SkiaDeviceDriver() override;
 
   /** Options */
   virtual int GetDeviceCaps(int caps_id);
 
   /** Save and restore all graphic states */
   virtual void SaveState();
   virtual void RestoreState(FX_BOOL bKeepSaved);
 
   /** Set clipping path using filled region */
   virtual FX_BOOL SetClip_PathFill(
@@ skipping 111 matching lines @@
                                        FX_BOOL bFill = TRUE);
   void SetClipMask(rasterizer_scanline_aa& rasterizer);
   void SetClipMask(SkPath& skPath, SkPaint* spaint);
   virtual uint8_t* GetBuffer() const { return m_pAggDriver->GetBuffer(); }
 
   CFX_AggDeviceDriver* m_pAggDriver;
 };
 #endif  // defined(_SKIA_SUPPORT_)
 
 #endif  // CORE_SRC_FXGE_SKIA_FX_SKIA_DEVICE_H_