Update {virtual,override,final} to follow C++11 style in chrome/browser/chromeos/drive.

chrome/browser/chromeos/drive/fileapi/fileapi_worker_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 "chrome/browser/chromeos/drive/fileapi/fileapi_worker.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_util.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 22 matching lines @@
 // close callback is called.
 class TestFileSystemForOpenFile : public DummyFileSystem {
  public:
   TestFileSystemForOpenFile(const base::FilePath& local_file_path,
                             OpenMode expected_open_mode)
       : local_file_path_(local_file_path),
         expected_open_mode_(expected_open_mode),
         closed_(false) {
   }
 
-  virtual void OpenFile(const base::FilePath& file_path,
-                        OpenMode open_mode,
-                        const std::string& mime_type,
-                        const drive::OpenFileCallback& callback) override {
+  void OpenFile(const base::FilePath& file_path,
+                OpenMode open_mode,
+                const std::string& mime_type,
+                const drive::OpenFileCallback& callback) override {
     EXPECT_EQ(expected_open_mode_, open_mode);
 
     callback.Run(
         FILE_ERROR_OK,
         local_file_path_,
         base::Bind(&TestFileSystemForOpenFile::Close, base::Unretained(this)));
   }
 
   void Close() {
     closed_ = true;
@@ skipping 200 matching lines @@
   OpenFile(kDummyPath,
            base::File::FLAG_OPEN | base::File::FLAG_READ,
            base::Bind(&VerifyRead, kInitialData),
            &file_system);
   content::RunAllBlockingPoolTasksUntilIdle();
   EXPECT_TRUE(file_system.closed());
 }
 
 }  // namespace fileapi_internal
 }  // namespace drive