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

Source/platform/graphics/DecodingImageGenerator.h

Index: Source/platform/graphics/DecodingImageGenerator.h
diff --git a/Source/platform/graphics/DecodingImageGenerator.h b/Source/platform/graphics/DecodingImageGenerator.h
index c7105ee69b8cfb0182d0fc4806220599b72846b3..d1fa5d4fa0032119dff6760548ec3482e3765718 100644
--- a/Source/platform/graphics/DecodingImageGenerator.h
+++ b/Source/platform/graphics/DecodingImageGenerator.h
@@ -48,14 +48,14 @@ 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;