Standardize usage of virtual/override/final in chrome/browser/

chrome/browser/gpu/three_d_api_observer.h

Index: chrome/browser/gpu/three_d_api_observer.h
diff --git a/chrome/browser/gpu/three_d_api_observer.h b/chrome/browser/gpu/three_d_api_observer.h
index 9181d1c62df329d48bc07b041fb46456507e6b85..fb38da93e2eabbdb98a84621df1b965afd8ed253 100644
--- a/chrome/browser/gpu/three_d_api_observer.h
+++ b/chrome/browser/gpu/three_d_api_observer.h
@@ -11,13 +11,13 @@
 class ThreeDAPIObserver : public content::GpuDataManagerObserver {
  public:
   ThreeDAPIObserver();
-  virtual ~ThreeDAPIObserver();
+  ~ThreeDAPIObserver() override;
 
  private:
-  virtual void DidBlock3DAPIs(const GURL& url,
-                              int render_process_id,
-                              int render_view_id,
-                              content::ThreeDAPIType requester) override;
+  void DidBlock3DAPIs(const GURL& url,
+                      int render_process_id,
+                      int render_view_id,
+                      content::ThreeDAPIType requester) override;
 
   DISALLOW_COPY_AND_ASSIGN(ThreeDAPIObserver);
 };