Add flag to enable immersive fullscreen for v2 apps

chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm

Index: chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
index 4e90233cb29795dc1396df752fc9df08c98a3818..93fc84678b7537ee723274d514b162e7916a97ea 100644
--- a/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/apps/native_app_window_cocoa.mm
@@ -427,7 +427,8 @@ bool NativeAppWindowCocoa::IsFullscreen() const {
   return is_fullscreen_;
 }
 
-void NativeAppWindowCocoa::SetFullscreen(bool fullscreen) {
+void NativeAppWindowCocoa::SetFullscreen(ShellWindow::FullscreenType type) {
+  bool fullscreen = (type != ShellWindow::FULLSCREEN_TYPE_NONE);
   if (fullscreen == is_fullscreen_)
     return;
   is_fullscreen_ = fullscreen;
@@ -483,8 +484,8 @@ void NativeAppWindowCocoa::SetFullscreen(bool fullscreen) {
   }
 }
 
-bool NativeAppWindowCocoa::IsFullscreenOrPending() const {
-  return is_fullscreen_;
+bool NativeAppWindowCocoa::SupportsImmersiveFullscreen() const {
+  return false;
 }
 
 bool NativeAppWindowCocoa::IsDetached() const {
@@ -571,7 +572,7 @@ void NativeAppWindowCocoa::Minimize() {
 }
 
 void NativeAppWindowCocoa::Restore() {
-  DCHECK(!IsFullscreenOrPending());   // SetFullscreen, not Restore, expected.
+  DCHECK(!is_fullscreen_);   // SetFullscreen, not Restore, expected.
 
   if (IsMaximized()) {
     is_maximized_ = false;  // See top of file NOTE: State Before Update.