Standardize usage of virtual/override/final in extensions/

extensions/browser/api/execute_code_function.h

Index: extensions/browser/api/execute_code_function.h
diff --git a/extensions/browser/api/execute_code_function.h b/extensions/browser/api/execute_code_function.h
index 611b4205c6175420cc96088c77a69352b54f10a3..9e1593a9d3ea3a87a120c11b925ab238a8327c11 100644
--- a/extensions/browser/api/execute_code_function.h
+++ b/extensions/browser/api/execute_code_function.h
@@ -19,11 +19,11 @@ class ExecuteCodeFunction : public AsyncExtensionFunction {
   ExecuteCodeFunction();
 
  protected:
-  virtual ~ExecuteCodeFunction();
+  ~ExecuteCodeFunction() override;
 
   // ExtensionFunction implementation.
-  virtual bool HasPermission() override;
-  virtual bool RunAsync() override;
+  bool HasPermission() override;
+  bool RunAsync() override;
 
   // Initialize |details_| if it hasn't already been.
   virtual bool Init() = 0;