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

base/prefs/json_pref_store_unittest.cc

Index: base/prefs/json_pref_store_unittest.cc
diff --git a/base/prefs/json_pref_store_unittest.cc b/base/prefs/json_pref_store_unittest.cc
index dc4043e32bec3a20627ade7550ca3a2927821659..ff68836014f65bcb780e8aac035224e79a61d655 100644
--- a/base/prefs/json_pref_store_unittest.cc
+++ b/base/prefs/json_pref_store_unittest.cc
@@ -86,7 +86,7 @@ class MockReadErrorDelegate : public PersistentPrefStore::ReadErrorDelegate {
 
 class JsonPrefStoreTest : public testing::Test {
  protected:
-  virtual void SetUp() override {
+  void SetUp() override {
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
 
     ASSERT_TRUE(PathService::Get(base::DIR_TEST_DATA, &data_dir_));
@@ -94,7 +94,7 @@ class JsonPrefStoreTest : public testing::Test {
     ASSERT_TRUE(PathExists(data_dir_));
   }
 
-  virtual void TearDown() override {
+  void TearDown() override {
     // Make sure all pending tasks have been processed (e.g., deleting the
     // JsonPrefStore may post write tasks).
     message_loop_.PostTask(FROM_HERE, MessageLoop::QuitWhenIdleClosure());