Standardize usage of virtual/override/final specifiers.

ui/message_center/views/message_popup_collection_unittest.cc

Index: ui/message_center/views/message_popup_collection_unittest.cc
diff --git a/ui/message_center/views/message_popup_collection_unittest.cc b/ui/message_center/views/message_popup_collection_unittest.cc
index 6aa0736e407240642572347f7611aa06f52c9601..1e8526e40715d150819356168e30d13a1b72c567 100644
--- a/ui/message_center/views/message_popup_collection_unittest.cc
+++ b/ui/message_center/views/message_popup_collection_unittest.cc
@@ -26,7 +26,7 @@ namespace test {
 
 class MessagePopupCollectionTest : public views::ViewsTestBase {
  public:
-  virtual void SetUp() override {
+  void SetUp() override {
     views::ViewsTestBase::SetUp();
     MessageCenter::Initialize();
     MessageCenter::Get()->DisableTimersForTest();
@@ -42,7 +42,7 @@ class MessagePopupCollectionTest : public views::ViewsTestBase {
     PrepareForWait();
   }
 
-  virtual void TearDown() override {
+  void TearDown() override {
     collection_.reset();
     MessageCenter::Shutdown();
     views::ViewsTestBase::TearDown();