Standardize usage of virtual/override/final in chrome/browser/drive/

chrome/browser/drive/drive_uploader.h

Index: chrome/browser/drive/drive_uploader.h
diff --git a/chrome/browser/drive/drive_uploader.h b/chrome/browser/drive/drive_uploader.h
index 717fc7da55d1d2edaff19b6507f69151bf24b0a6..857b65b97da3a634d292ca2a5757d3991fb464c3 100644
--- a/chrome/browser/drive/drive_uploader.h
+++ b/chrome/browser/drive/drive_uploader.h
@@ -115,10 +115,10 @@ class DriveUploader : public DriveUploaderInterface {
  public:
   DriveUploader(DriveServiceInterface* drive_service,
                 const scoped_refptr<base::TaskRunner>& blocking_task_runner);
-  virtual ~DriveUploader();
+  ~DriveUploader() override;
 
   // DriveUploaderInterface overrides.
-  virtual google_apis::CancelCallback UploadNewFile(
+  google_apis::CancelCallback UploadNewFile(
       const std::string& parent_resource_id,
       const base::FilePath& local_file_path,
       const std::string& title,
@@ -126,14 +126,14 @@ class DriveUploader : public DriveUploaderInterface {
       const UploadNewFileOptions& options,
       const UploadCompletionCallback& callback,
       const google_apis::ProgressCallback& progress_callback) override;
-  virtual google_apis::CancelCallback UploadExistingFile(
+  google_apis::CancelCallback UploadExistingFile(
       const std::string& resource_id,
       const base::FilePath& local_file_path,
       const std::string& content_type,
       const UploadExistingFileOptions& options,
       const UploadCompletionCallback& callback,
       const google_apis::ProgressCallback& progress_callback) override;
-  virtual google_apis::CancelCallback ResumeUploadFile(
+  google_apis::CancelCallback ResumeUploadFile(
       const GURL& upload_location,
       const base::FilePath& local_file_path,
       const std::string& content_type,