MacViews: Implement CloseNow() as just -[NSWindow close].

ui/views/widget/native_widget_mac.h

Index: ui/views/widget/native_widget_mac.h
diff --git a/ui/views/widget/native_widget_mac.h b/ui/views/widget/native_widget_mac.h
index 59867c02b5435ce425dba2d8c6031f52aa645e11..580dacfbdad6b4ab51e105c8df9febde0a6fa110 100644
--- a/ui/views/widget/native_widget_mac.h
+++ b/ui/views/widget/native_widget_mac.h
@@ -38,8 +38,9 @@ class VIEWS_EXPORT NativeWidgetMac : public internal::NativeWidgetPrivate {
   bool IsWindowModalSheet() const;
 
   // Deletes |bridge_| and informs |delegate_| that the native widget is
-  // destroyed. This is usually called from the NSWindowDelegate.
-  void OnWindowWillClose();
+  // destroyed. BridgedNativeWidget::OnWindowWillClose() calls this when the
+  // NSWindowDelegate informs the bridge that the window is being closed.
+  void OnWindowDestroyed();
 
   // Returns the vertical position that sheets should be anchored, in pixels
   // from the bottom of the window.