Replace OVERRIDE with its C++11 counterparts in src/skia

skia/ext/opacity_draw_filter.h

Index: skia/ext/opacity_draw_filter.h
diff --git a/skia/ext/opacity_draw_filter.h b/skia/ext/opacity_draw_filter.h
index a2a686cad8da38fa6f50076ce1da476e4d379315..9789cc2a1fb93b2d100434a8edc6bcacc1478da2 100644
--- a/skia/ext/opacity_draw_filter.h
+++ b/skia/ext/opacity_draw_filter.h
@@ -20,7 +20,7 @@ class SK_API OpacityDrawFilter : public SkDrawFilter {
  public:
   OpacityDrawFilter(float opacity, bool disable_image_filtering);
   virtual ~OpacityDrawFilter();
-  virtual bool filter(SkPaint* paint, SkDrawFilter::Type type) OVERRIDE;
+  virtual bool filter(SkPaint* paint, SkDrawFilter::Type type) override;
 
  private:
   int alpha_;