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

chrome/browser/captive_portal/captive_portal_tab_reloader_unittest.cc

Index: chrome/browser/captive_portal/captive_portal_tab_reloader_unittest.cc
diff --git a/chrome/browser/captive_portal/captive_portal_tab_reloader_unittest.cc b/chrome/browser/captive_portal/captive_portal_tab_reloader_unittest.cc
index bd003fb2cdfe9946177e5d6504d1527d08f59754..ccbcd038f40eb45aa07fe96fa36eb91dc47c7d13 100644
--- a/chrome/browser/captive_portal/captive_portal_tab_reloader_unittest.cc
+++ b/chrome/browser/captive_portal/captive_portal_tab_reloader_unittest.cc
@@ -73,14 +73,11 @@ class MockInterstitialPageDelegate : public content::InterstitialPageDelegate {
     interstitial_page->Show();
   }
 
-  virtual ~MockInterstitialPageDelegate() {
-  }
+  ~MockInterstitialPageDelegate() override {}
 
  private:
   // InterstitialPageDelegate implementation:
-  virtual std::string GetHTMLContents() override {
-    return "HTML Contents";
-  }
+  std::string GetHTMLContents() override { return "HTML Contents"; }
 
   DISALLOW_COPY_AND_ASSIGN(MockInterstitialPageDelegate);
 };