Standardize usage of virtual/override/final in ui/

ui/app_list/app_list_folder_item.cc

Index: ui/app_list/app_list_folder_item.cc
diff --git a/ui/app_list/app_list_folder_item.cc b/ui/app_list/app_list_folder_item.cc
index 3c5634d0c288bc9585c3ff2ee15ec319fa6b3e54..120d48e219e10ef82365500fefdb69295dcb6314 100644
--- a/ui/app_list/app_list_folder_item.cc
+++ b/ui/app_list/app_list_folder_item.cc
@@ -29,7 +29,7 @@ class FolderImageSource : public gfx::CanvasImageSource {
     DCHECK(icons.size() <= kNumFolderTopItems);
   }
 
-  virtual ~FolderImageSource() {}
+  ~FolderImageSource() override {}
 
  private:
   void DrawIcon(gfx::Canvas* canvas,
@@ -47,7 +47,7 @@ class FolderImageSource : public gfx::CanvasImageSource {
   }
 
   // gfx::CanvasImageSource overrides:
-  virtual void Draw(gfx::Canvas* canvas) override {
+  void Draw(gfx::Canvas* canvas) override {
     // Draw folder circle.
     gfx::Point center = gfx::Point(size().width() / 2 , size().height() / 2);
     SkPaint paint;