Standardize usage of virtual/override/final in components/

components/favicon_base/select_favicon_frames.cc

Index: components/favicon_base/select_favicon_frames.cc
diff --git a/components/favicon_base/select_favicon_frames.cc b/components/favicon_base/select_favicon_frames.cc
index d53225d9c919287fc2eef814c909e7c4060fb6a0..492d21196df31964c5b9e8fce9a49d1e3af66b00 100644
--- a/components/favicon_base/select_favicon_frames.cc
+++ b/components/favicon_base/select_favicon_frames.cc
@@ -171,10 +171,10 @@ SkBitmap GetResizedBitmap(const SkBitmap& source_bitmap,
 class FaviconImageSource : public gfx::ImageSkiaSource {
  public:
   FaviconImageSource() {}
-  virtual ~FaviconImageSource() {}
+  ~FaviconImageSource() override {}
 
   // gfx::ImageSkiaSource:
-  virtual gfx::ImageSkiaRep GetImageForScale(float scale) override {
+  gfx::ImageSkiaRep GetImageForScale(float scale) override {
     const gfx::ImageSkiaRep* rep = NULL;
     // gfx::ImageSkia passes one of the resource scale factors. The source
     // should return: