Standardize usage of virtual/override/final specifiers in base/.

base/memory/singleton_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/at_exit.h"
 #include "base/memory/singleton.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
@@ skipping 135 matching lines @@
 CallbackFunc* GetStaticSingleton() {
   return &CallbackSingletonWithStaticTrait::GetInstance()->callback_;
 }
 
 }  // namespace
 
 class SingletonTest : public testing::Test {
  public:
   SingletonTest() {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     non_leak_called_ = false;
     leaky_called_ = false;
     static_called_ = false;
   }
 
  protected:
   void VerifiesCallbacks() {
     EXPECT_TRUE(non_leak_called_);
     EXPECT_FALSE(leaky_called_);
     EXPECT_TRUE(static_called_);
@@ skipping 111 matching lines @@
   AlignedTestSingleton<AlignedMemory<128, 128> >* align128 =
       AlignedTestSingleton<AlignedMemory<128, 128> >::GetInstance();
   AlignedTestSingleton<AlignedMemory<4096, 4096> >* align4096 =
       AlignedTestSingleton<AlignedMemory<4096, 4096> >::GetInstance();
 
   EXPECT_ALIGNED(align4, 4);
   EXPECT_ALIGNED(align32, 32);
   EXPECT_ALIGNED(align128, 128);
   EXPECT_ALIGNED(align4096, 4096);
 }