[MacViews] Add NativeAppWindowViewsMac and port HideWithApp behavior from NativeAppWindowCocoa.

chrome/browser/ui/views/apps/chrome_app_window_client_views_mac.mm

Index: chrome/browser/ui/views/apps/chrome_app_window_client_views_mac.mm
diff --git a/chrome/browser/ui/views/apps/chrome_app_window_client_views_mac.mm b/chrome/browser/ui/views/apps/chrome_app_window_client_views_mac.mm
index c87fc4f94438ecf2e0246b4282620c3de826f470..01b5229583936d6c95caa3342fe3c7ea661735c3 100644
--- a/chrome/browser/ui/views/apps/chrome_app_window_client_views_mac.mm
+++ b/chrome/browser/ui/views/apps/chrome_app_window_client_views_mac.mm
@@ -4,13 +4,13 @@
 
 #include "chrome/browser/ui/apps/chrome_app_window_client.h"
 
-#include "chrome/browser/ui/views/apps/chrome_native_app_window_views.h"
+#include "chrome/browser/ui/views/apps/chrome_native_app_window_views_mac.h"
 
 // static
 extensions::NativeAppWindow* ChromeAppWindowClient::CreateNativeAppWindowImpl(
     extensions::AppWindow* app_window,
     const extensions::AppWindow::CreateParams& params) {
-  ChromeNativeAppWindowViews* window = new ChromeNativeAppWindowViews;
+  ChromeNativeAppWindowViewsMac* window = new ChromeNativeAppWindowViewsMac;
   window->Init(app_window, params);
   return window;
 }