Standardize usage of virtual/override/final specifiers.

extensions/browser/quota_service_unittest.cc

Index: extensions/browser/quota_service_unittest.cc
diff --git a/extensions/browser/quota_service_unittest.cc b/extensions/browser/quota_service_unittest.cc
index 62ba170c1e8bcc93d9f5c33d73ea564e66689f97..5bd04007a766f5c218c3c53cad0687934c6ab68a 100644
--- a/extensions/browser/quota_service_unittest.cc
+++ b/extensions/browser/quota_service_unittest.cc
@@ -128,8 +128,8 @@ class QuotaServiceTest : public testing::Test {
         extension_c_("c"),
         loop_(),
         ui_thread_(BrowserThread::UI, &loop_) {}
-  virtual void SetUp() { service_.reset(new QuotaService()); }
-  virtual void TearDown() {
+  void SetUp() override { service_.reset(new QuotaService()); }
+  void TearDown() override {
     loop_.RunUntilIdle();
     service_.reset();
   }