Standardize usage of virtual/override/final in storage/

storage/browser/fileapi/sandbox_file_system_backend_delegate.cc

 // Copyright 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 "storage/browser/fileapi/sandbox_file_system_backend_delegate.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
@@ skipping 74 matching lines @@
   known_type_strings.insert(kSyncableDirectoryName);
   return known_type_strings;
 }
 
 class ObfuscatedOriginEnumerator
     : public SandboxFileSystemBackendDelegate::OriginEnumerator {
  public:
   explicit ObfuscatedOriginEnumerator(ObfuscatedFileUtil* file_util) {
     enum_.reset(file_util->CreateOriginEnumerator());
   }
-  virtual ~ObfuscatedOriginEnumerator() {}
+  ~ObfuscatedOriginEnumerator() override {}
 
-  virtual GURL Next() override {
-    return enum_->Next();
-  }
+  GURL Next() override { return enum_->Next(); }
 
-  virtual bool HasFileSystemType(FileSystemType type) const override {
+  bool HasFileSystemType(FileSystemType type) const override {
     return enum_->HasTypeDirectory(
         SandboxFileSystemBackendDelegate::GetTypeString(type));
   }
 
  private:
   scoped_ptr<ObfuscatedFileUtil::AbstractOriginEnumerator> enum_;
 };
 
 void OpenFileSystemOnFileTaskRunner(
     ObfuscatedFileUtil* file_util,
@@ skipping 552 matching lines @@
   return new ObfuscatedFileUtil(special_storage_policy,
                                 file_system_directory,
                                 env_override,
                                 file_task_runner,
                                 base::Bind(&GetTypeStringForURL),
                                 GetKnownTypeStrings(),
                                 NULL);
 }
 
 }  // namespace storage