Standardize usage of virtual/override/final specifiers.

chrome/browser/apps/drive/drive_app_converter_browsertest.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 "chrome/browser/apps/drive/drive_app_converter.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 21 matching lines @@
 namespace {
 
 const char kAppName[] = "Test drive app";
 const char kAppUrl[] = "http://foobar.com/drive_app";
 
 }  // namespace
 
 class DriveAppConverterTest : public ExtensionBrowserTest {
  public:
   DriveAppConverterTest() {}
-  virtual ~DriveAppConverterTest() {}
+  ~DriveAppConverterTest() override {}
 
   // ExtensionBrowserTest:
   void SetUpOnMainThread() override {
     ExtensionBrowserTest::SetUpOnMainThread();
 
     base::FilePath test_data_dir;
     PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir);
     embedded_test_server()->ServeFilesFromDirectory(test_data_dir);
     ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());
   }
@@ skipping 97 matching lines @@
   InstallAndWaitFinish(GetTestDriveApp());
   const Extension* second_install = converter()->extension();
   ASSERT_TRUE(second_install != NULL);
   EXPECT_FALSE(converter()->is_new_install());
 
   // Two different app instances.
   ASSERT_NE(first_install, second_install);
   EXPECT_EQ(first_install_id, second_install->id());
   EXPECT_GE(second_install->version()->CompareTo(first_install_version), 0);
 }