Fix chromium-style errors (#12802)

atom/browser/api/atom_api_power_monitor_mac.mm

@@ -44,13 +44,13 @@
 }
 
 - (void)onScreenLocked:(NSNotification*)notification {
-  for (auto& emitter : self->emitters) {
+  for (auto*& emitter : self->emitters) {
     emitter->Emit("lock-screen");
   }
 }
 
 - (void)onScreenUnlocked:(NSNotification*)notification {
-  for (auto& emitter : self->emitters) {
+  for (auto*& emitter : self->emitters) {
     emitter->Emit("unlock-screen");
   }
 }

atom/browser/ui/views/frameless_view.h

@@ -18,7 +18,7 @@ class NativeWindowViews;
 class FramelessView : public views::NonClientFrameView {
  public:
   FramelessView();
-  virtual ~FramelessView();
+  ~FramelessView() override;
 
   virtual void Init(NativeWindowViews* window, views::Widget* frame);
 

atom/browser/ui/views/menu_model_adapter.h

@@ -13,7 +13,7 @@ namespace atom {
 class MenuModelAdapter : public views::MenuModelAdapter {
  public:
   explicit MenuModelAdapter(AtomMenuModel* menu_model);
-  virtual ~MenuModelAdapter();
+  ~MenuModelAdapter() override;
 
  protected:
   bool GetAccelerator(int id, ui::Accelerator* accelerator) const override;