Add flag to enable immersive fullscreen for v2 apps

ash/wm/window_state.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/window_state.h"
 
 #include "ash/root_window_controller.h"
 #include "ash/screen_ash.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/window_properties.h"
@@ skipping 152 matching lines @@
 }
 
 void WindowState::ToggleMaximized() {
   if (IsMaximized())
     Restore();
   else if (CanMaximize())
     Maximize();
 }
 
 void WindowState::ToggleFullscreen() {
-  // Window which cannot be maximized should not be fullscreened.
-  // It can, however, be restored if it was fullscreened.
   bool is_fullscreen = IsFullscreen();
-  if (!is_fullscreen && !CanMaximize())
-    return;
-  if (delegate_ && delegate_->ToggleFullscreen(this))
-    return;
   if (is_fullscreen) {
-    Restore();
+    if (delegate_ && delegate_->ExitFullscreen(this))
+      return;
+   Restore();
   } else {
-    window_->SetProperty(aura::client::kShowStateKey,
-                         ui::SHOW_STATE_FULLSCREEN);
+    // Windows which cannot be maximized should not be fullscreened.
+    if (CanMaximize()) {
+      if (delegate_ && delegate_->EnterImmersiveFullscreen(this))
+        return;
+
+      window_->SetProperty(aura::client::kShowStateKey,
+                           ui::SHOW_STATE_FULLSCREEN);
+    }
   }
 }
 
 void WindowState::SetBoundsInScreen(
     const gfx::Rect& bounds_in_screen) {
   gfx::Rect bounds_in_parent =
       ScreenAsh::ConvertRectFromScreen(window_->parent(),
                                        bounds_in_screen);
   window_->SetBounds(bounds_in_parent);
 }
@@ skipping 105 matching lines @@
   }
   return settings;
 }
 
 const WindowState* GetWindowState(const aura::Window* window) {
   return GetWindowState(const_cast<aura::Window*>(window));
 }
 
 }  // namespace wm
 }  // namespace ash