cros: Remove some OS platform ifdefs from ash

ash/app_list/app_list_presenter_delegate.cc

 // Copyright (c) 2012 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/app_list/app_list_presenter_delegate.h"
 
 #include "ash/aura/wm_window_aura.h"
 #include "ash/common/ash_switches.h"
 #include "ash/common/shelf/app_list_button.h"
 #include "ash/common/shelf/shelf_layout_manager.h"
@@ skipping 43 matching lines @@
     bounds.Subtract(keyboard_controller->current_keyboard_bounds());
 
   // Apply the |minimum_height|.
   if (bounds.height() < minimum_height)
     bounds.set_height(minimum_height);
 
   return bounds.CenterPoint();
 }
 
 bool IsFullscreenAppListEnabled() {
-#if defined(OS_CHROMEOS)
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kAshEnableFullscreenAppList);
-#else
-  return false;
-#endif
 }
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListPresenterDelegate, public:
 
 AppListPresenterDelegate::AppListPresenterDelegate(
     app_list::AppListPresenterImpl* presenter,
     app_list::AppListViewDelegateFactory* view_delegate_factory)
@@ skipping 197 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListPresenterDelegate, WmShelfObserver implementation:
 
 void AppListPresenterDelegate::OnShelfIconPositionsChanged() {
   UpdateBounds();
 }
 
 }  // namespace ash