Fix virtual/override/final usage in Source/platform/.

Source/platform/graphics/DecodingImageGenerator.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 30 matching lines @@
 // Implements SkImageGenerator and used by SkPixelRef to populate a discardable
 // memory with decoded pixels.
 //
 // This class does not own an ImageDecode. It does not own encoded data. It serves
 // as and adapter to ImageFrameGenerator which actually performs decoding.
 class PLATFORM_EXPORT DecodingImageGenerator final : public SkImageGenerator {
 public:
     static SkImageGenerator* create(SkData*);
 
     DecodingImageGenerator(PassRefPtr<ImageFrameGenerator>, const SkImageInfo&, size_t index);
-    virtual ~DecodingImageGenerator();
+    ~DecodingImageGenerator() override;
 
     void setGenerationId(size_t id) { m_generationId = id; }
 
 protected:
-    virtual SkData* onRefEncodedData() override;
-    virtual Result onGetPixels(const SkImageInfo&, void* pixels, size_t rowBytes, const Options&, SkPMColor ctable[], int* ctableCount) override;
-    virtual bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], SkYUVColorSpace*) override;
+    SkData* onRefEncodedData() override;
+    Result onGetPixels(const SkImageInfo&, void* pixels, size_t rowBytes, const Options&, SkPMColor ctable[], int* ctableCount) override;
+    bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], SkYUVColorSpace*) override;
 
 private:
     RefPtr<ImageFrameGenerator> m_frameGenerator;
     size_t m_frameIndex;
     size_t m_generationId;
 };
 
 } // namespace blink
 
 #endif // DecodingImageGenerator_h_