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

Source/platform/image-decoders/jpeg/JPEGImageDecoder.h

Index: Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
diff --git a/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h b/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
index 5e24b4392eb630e2a85dc35e7475028c7858c8dd..1f89a902be78fb397995677cda36643aeb8c2e5d 100644
--- a/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
+++ b/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
@@ -41,17 +41,17 @@ class PLATFORM_EXPORT JPEGImageDecoder : public ImageDecoder {
     WTF_MAKE_NONCOPYABLE(JPEGImageDecoder);
 public:
     JPEGImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption, size_t maxDecodedBytes);
-    virtual ~JPEGImageDecoder();
+    ~JPEGImageDecoder() override;
 
     // ImageDecoder:
-    virtual String filenameExtension() const override { return "jpg"; }
-    virtual bool hasColorProfile() const override { return m_hasColorProfile; }
-    virtual IntSize decodedSize() const override { return m_decodedSize; }
-    virtual IntSize decodedYUVSize(int component, SizeType) const override;
-    virtual bool setSize(unsigned width, unsigned height) override;
-    virtual bool canDecodeToYUV() override;
-    virtual bool decodeToYUV() override;
-    virtual void setImagePlanes(PassOwnPtr<ImagePlanes>) override;
+    String filenameExtension() const override { return "jpg"; }
+    bool hasColorProfile() const override { return m_hasColorProfile; }
+    IntSize decodedSize() const override { return m_decodedSize; }
+    IntSize decodedYUVSize(int component, SizeType) const override;
+    bool setSize(unsigned width, unsigned height) override;
+    bool canDecodeToYUV() override;
+    bool decodeToYUV() override;
+    void setImagePlanes(PassOwnPtr<ImagePlanes>) override;
     bool hasImagePlanes() const { return m_imagePlanes; }
 
     bool outputScanlines();
@@ -64,8 +64,8 @@ public:
 
 private:
     // ImageDecoder:
-    virtual void decodeSize() override { decode(true); }
-    virtual void decode(size_t) override { decode(false); }
+    void decodeSize() override { decode(true); }
+    void decode(size_t) override { decode(false); }
 
     // Decodes the image.  If |onlySize| is true, stops decoding after
     // calculating the image size.  If decoding fails but there is no more