Standardize usage of virtual/override/final in gin/

gin/modules/module_runner_delegate.h

Index: gin/modules/module_runner_delegate.h
diff --git a/gin/modules/module_runner_delegate.h b/gin/modules/module_runner_delegate.h
index 421e23a866eda94b0373ecd6e711ba49c6a0dcfb..bd174f0822f491c278b0addbef759bc8eed337c4 100644
--- a/gin/modules/module_runner_delegate.h
+++ b/gin/modules/module_runner_delegate.h
@@ -26,7 +26,7 @@ class GIN_EXPORT ModuleRunnerDelegate : public ShellRunnerDelegate {
  public:
   explicit ModuleRunnerDelegate(
       const std::vector<base::FilePath>& search_paths);
-  virtual ~ModuleRunnerDelegate();
+  ~ModuleRunnerDelegate() override;
 
   void AddBuiltinModule(const std::string& id, ModuleGetter getter);
   void AddBuiltinModule(const std::string& id,
@@ -39,11 +39,11 @@ class GIN_EXPORT ModuleRunnerDelegate : public ShellRunnerDelegate {
   typedef std::map<std::string, ModuleGetterCallback> BuiltinModuleMap;
 
   // From ShellRunnerDelegate:
-  virtual v8::Handle<v8::ObjectTemplate> GetGlobalTemplate(
+  v8::Handle<v8::ObjectTemplate> GetGlobalTemplate(
       ShellRunner* runner,
       v8::Isolate* isolate) override;
-  virtual void DidCreateContext(ShellRunner* runner) override;
-  virtual void DidRunScript(ShellRunner* runner) override;
+  void DidCreateContext(ShellRunner* runner) override;
+  void DidRunScript(ShellRunner* runner) override;
 
   BuiltinModuleMap builtin_modules_;
   FileModuleProvider module_provider_;