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

chrome/browser/chromeos/drive/fileapi/fileapi_worker_unittest.cc

Index: chrome/browser/chromeos/drive/fileapi/fileapi_worker_unittest.cc
diff --git a/chrome/browser/chromeos/drive/fileapi/fileapi_worker_unittest.cc b/chrome/browser/chromeos/drive/fileapi/fileapi_worker_unittest.cc
index b004cff4e74b65ca3fc6761bb271350698c87667..4caccde0538ccf0bbd750b105419b151450a7995 100644
--- a/chrome/browser/chromeos/drive/fileapi/fileapi_worker_unittest.cc
+++ b/chrome/browser/chromeos/drive/fileapi/fileapi_worker_unittest.cc
@@ -40,10 +40,10 @@ class TestFileSystemForOpenFile : public DummyFileSystem {
         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(