Standardize usage of virtual/override/final specifiers.

extensions/browser/runtime_data_unittest.cc

 // Copyright 2014 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 "extensions/browser/runtime_data.h"
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "extensions/browser/extension_registry.h"
@@ skipping 14 matching lines @@
              .Set("name", "test")
              .Set("version", "0.1")
              .Set("background", DictionaryBuilder().Set("page", "bg.html")))
       .SetID("id2")
       .Build();
 }
 
 class RuntimeDataTest : public testing::Test {
  public:
   RuntimeDataTest() : registry_(NULL), runtime_data_(&registry_) {}
-  virtual ~RuntimeDataTest() {}
+  ~RuntimeDataTest() override {}
 
  protected:
   ExtensionRegistry registry_;
   RuntimeData runtime_data_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(RuntimeDataTest);
 };
 
 TEST_F(RuntimeDataTest, IsBackgroundPageReady) {
@@ skipping 45 matching lines @@
   runtime_data_.SetBackgroundPageReady(extension.get(), true);
   ASSERT_TRUE(runtime_data_.HasExtensionForTesting(extension.get()));
 
   runtime_data_.OnExtensionUnloaded(
       NULL, extension.get(), UnloadedExtensionInfo::REASON_DISABLE);
   EXPECT_FALSE(runtime_data_.HasExtensionForTesting(extension.get()));
 }
 
 }  // namespace
 }  // namespace extensions