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

chrome/browser/icon_manager.h

Index: chrome/browser/icon_manager.h
diff --git a/chrome/browser/icon_manager.h b/chrome/browser/icon_manager.h
index 2d42fe55e6b4a08620ef3b1e6959950a0460119d..01423817fefbb340080cefdfc07eb0cdd60b329e 100644
--- a/chrome/browser/icon_manager.h
+++ b/chrome/browser/icon_manager.h
@@ -55,7 +55,7 @@
 class IconManager : public IconLoader::Delegate {
  public:
   IconManager();
-  virtual ~IconManager();
+  ~IconManager() override;
 
   // Synchronous call to examine the internal caches for the icon. Returns the
   // icon if we have already loaded it, NULL if we don't have it and must load
@@ -84,11 +84,10 @@ class IconManager : public IconLoader::Delegate {
       base::CancelableTaskTracker* tracker);
 
   // IconLoader::Delegate interface.
-  virtual bool OnGroupLoaded(IconLoader* loader,
-                             const IconGroupID& group) override;
-  virtual bool OnImageLoaded(IconLoader* loader,
-                             gfx::Image* result,
-                             const IconGroupID& group) override;
+  bool OnGroupLoaded(IconLoader* loader, const IconGroupID& group) override;
+  bool OnImageLoaded(IconLoader* loader,
+                     gfx::Image* result,
+                     const IconGroupID& group) override;
 
  private:
   struct CacheKey {