Standardize usage of virtual/override/final in content/

content/test/test_content_client.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_TEST_TEST_CONTENT_CLIENT_H_
 #define CONTENT_TEST_TEST_CONTENT_CLIENT_H_
 
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "content/public/common/content_client.h"
 #include "ui/base/resource/data_pack.h"
 
 namespace content {
 
 class TestContentClient : public ContentClient {
  public:
   TestContentClient();
-  virtual ~TestContentClient();
+  ~TestContentClient() override;
 
   // ContentClient:
-  virtual std::string GetUserAgent() const override;
-  virtual base::StringPiece GetDataResource(
+  std::string GetUserAgent() const override;
+  base::StringPiece GetDataResource(
       int resource_id,
       ui::ScaleFactor scale_factor) const override;
 
  private:
   ui::DataPack data_pack_;
 
   DISALLOW_COPY_AND_ASSIGN(TestContentClient);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_TEST_CONTENT_CLIENT_H_