Use MD-ash's auto hide behavior for arc++ windows.

ash/common/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/common/wm/window_state.h"
 
 #include <utility>
 
 #include "ash/common/wm/default_state.h"
 #include "ash/common/wm/window_positioning_utils.h"
@@ skipping 289 matching lines @@
 
 WindowState::WindowState(WmWindow* window)
     : window_(window),
       window_position_managed_(false),
       bounds_changed_by_user_(false),
       panel_attached_(true),
       ignored_by_shelf_(false),
       can_consume_system_keys_(false),
       unminimize_to_restore_bounds_(false),
       in_immersive_fullscreen_(false),
-      hide_shelf_when_fullscreen_(true),
       minimum_visibility_(false),
       can_be_dragged_(true),
       cached_always_on_top_(false),
       ignore_property_change_(false),
       current_state_(new DefaultState(ToWindowStateType(GetShowState()))) {}
 
 bool WindowState::GetAlwaysOnTop() const {
   return window_->IsAlwaysOnTop();
 }
 
@@ skipping 75 matching lines @@
   if (!window_->GetTargetVisibility()) {
     SetBoundsConstrained(new_bounds);
     return;
   }
 
   window_->SetBoundsDirectCrossFade(new_bounds);
 }
 
 }  // namespace wm
 }  // namespace ash