Standardize usage of virtual/override/final specifiers.

chrome/browser/apps/drive/drive_app_provider_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_provider.h"
 
 #include <set>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 73 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(FakeUninstallSyncService);
 };
 
 }  // namespace
 
 class DriveAppProviderTest : public ExtensionBrowserTest,
                              public extensions::InstallObserver {
  public:
   DriveAppProviderTest() {}
-  virtual ~DriveAppProviderTest() {}
+  ~DriveAppProviderTest() override {}
 
   // ExtensionBrowserTest:
   void SetUpOnMainThread() override {
     ExtensionBrowserTest::SetUpOnMainThread();
 
     fake_drive_service_.reset(new drive::FakeDriveService);
     fake_drive_service_->LoadAppListForDriveApi("drive/applist_empty.json");
     apps_registry_.reset(
         new drive::DriveAppRegistry(fake_drive_service_.get()));
 
@@ skipping 469 matching lines @@
       chrome_app_id, ExtensionRegistry::EVERYTHING));
 
   // Uninstall is removed from sync and the app is added again.
   provider()->RemoveUninstalledDriveAppFromSync(kDriveAppId);
   WaitForPendingDriveAppConverters();
   chrome_app_id = mapping()->GetChromeApp(kDriveAppId);
   EXPECT_FALSE(chrome_app_id.empty());
   EXPECT_TRUE(ExtensionRegistry::Get(profile())->GetExtensionById(
       chrome_app_id, ExtensionRegistry::EVERYTHING));
 }