C++11 override should now be supported by all of {bots,Chrome,Android,Mozilla}

NOPRESUBMIT=true

BUG=skia:
DOCS_PREVIEW= https://skia.org/?cl=1037793002

Review URL: https://codereview.chromium.org/1037793002
diff --git a/src/images/SkImageDecoder_libgif.cpp b/src/images/SkImageDecoder_libgif.cpp
index b0ed810..5d55a13 100644
--- a/src/images/SkImageDecoder_libgif.cpp
+++ b/src/images/SkImageDecoder_libgif.cpp
@@ -19,12 +19,12 @@
 
 class SkGIFImageDecoder : public SkImageDecoder {
 public:
-    Format getFormat() const SK_OVERRIDE {
+    Format getFormat() const override {
         return kGIF_Format;
     }
 
 protected:
-    Result onDecode(SkStream* stream, SkBitmap* bm, Mode mode) SK_OVERRIDE;
+    Result onDecode(SkStream* stream, SkBitmap* bm, Mode mode) override;
 
 private:
     typedef SkImageDecoder INHERITED;