Update {virtual,override} to follow C++11 style in chrome.

chrome/browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api_unittest.cc

 // Copyright (c) 2013 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/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 150 matching lines @@
     // Set the Enterprise install attributes.
     stub_install_attributes_.SetDomain("google.com");
     stub_install_attributes_.SetRegistrationUser("test@google.com");
     stub_install_attributes_.SetDeviceId("device_id");
     stub_install_attributes_.SetMode(policy::DEVICE_MODE_ENTERPRISE);
 
     settings_helper_.ReplaceProvider(chromeos::kDeviceAttestationEnabled);
     settings_helper_.SetBoolean(chromeos::kDeviceAttestationEnabled, true);
   }
 
-  virtual void SetUp() override {
+  void SetUp() override {
     BrowserWithTestWindowTest::SetUp();
 
     // Set the user preferences.
     prefs_ = browser()->profile()->GetPrefs();
     base::ListValue whitelist;
     whitelist.AppendString(extension_->id());
     prefs_->Set(prefs::kAttestationExtensionWhitelist, whitelist);
 
     SetAuthenticatedUser();
   }
@@ skipping 333 matching lines @@
   }
 };
 
 TEST_F(EPKPChallengeUserKeyUnmanagedUserTest, UserNotManaged) {
   EXPECT_EQ(EPKPChallengeKeyBase::kUserNotManaged,
             utils::RunFunctionAndReturnError(func_.get(), kArgs, browser()));
 }
 
 }  // namespace
 }  // namespace extensions