Fix up all the easy virtual ... SK_OVERRIDE cases.

src/images/SkImageDecoder_libgif.cpp

Index: src/images/SkImageDecoder_libgif.cpp
diff --git a/src/images/SkImageDecoder_libgif.cpp b/src/images/SkImageDecoder_libgif.cpp
index 1d0e500206a5dac6673431d50a40147574e17028..0701eb68ae57022f97463d10c39ab858be4e030f 100644
--- a/src/images/SkImageDecoder_libgif.cpp
+++ b/src/images/SkImageDecoder_libgif.cpp
@@ -19,12 +19,12 @@
 
 class SkGIFImageDecoder : public SkImageDecoder {
 public:
-    virtual Format getFormat() const SK_OVERRIDE {
+    Format getFormat() const SK_OVERRIDE {
         return kGIF_Format;
     }
 
 protected:
-    virtual Result onDecode(SkStream* stream, SkBitmap* bm, Mode mode) SK_OVERRIDE;
+    Result onDecode(SkStream* stream, SkBitmap* bm, Mode mode) SK_OVERRIDE;
 
 private:
     typedef SkImageDecoder INHERITED;