Standardize usage of virtual/override/final in components/

components/precache/core/precache_fetcher_unittest.cc

Index: components/precache/core/precache_fetcher_unittest.cc
diff --git a/components/precache/core/precache_fetcher_unittest.cc b/components/precache/core/precache_fetcher_unittest.cc
index 0961a3c2b7d0263560b42844e1112efeedace994..999e51c849c0d5be519dd90d1070b125873a0623 100644
--- a/components/precache/core/precache_fetcher_unittest.cc
+++ b/components/precache/core/precache_fetcher_unittest.cc
@@ -60,9 +60,7 @@ class TestPrecacheDelegate : public PrecacheFetcher::PrecacheDelegate {
  public:
   TestPrecacheDelegate() : was_on_done_called_(false) {}
 
-  virtual void OnDone() override {
-    was_on_done_called_ = true;
-  }
+  void OnDone() override { was_on_done_called_ = true; }
 
   bool was_on_done_called() const {
     return was_on_done_called_;