Use platform's device scale factor for cursor

ash/wm/ash_native_cursor_manager.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/wm/ash_native_cursor_manager.h"
 
 #include "ash/display/cursor_window_controller.h"
 #include "ash/display/display_controller.h"
 #include "ash/shell.h"
 #include "ash/wm/image_cursors.h"
@@ skipping 77 matching lines @@
     image_cursors_->SetPlatformCursor(&new_cursor);
   } else {
     gfx::NativeCursor invisible_cursor(ui::kCursorNone);
     image_cursors_->SetPlatformCursor(&invisible_cursor);
     if (new_cursor == ui::kCursorCustom) {
       new_cursor = invisible_cursor;
     } else {
       new_cursor.SetPlatformCursor(invisible_cursor.platform());
     }
   }
-  new_cursor.set_device_scale_factor(
-      image_cursors_->GetDisplay().device_scale_factor());
+  new_cursor.set_device_scale_factor(image_cursors_->GetScale());
 
   delegate->CommitCursor(new_cursor);
 
   if (delegate->IsCursorVisible())
     SetCursorOnAllRootWindows(new_cursor);
 }
 
 void AshNativeCursorManager::SetCursorSet(
     ui::CursorSetType cursor_set,
     ::wm::NativeCursorManagerDelegate* delegate) {
@@ skipping 36 matching lines @@
         disabled_cursor_location_);
   } else {
     disabled_cursor_location_ = aura::Env::GetInstance()->last_mouse_location();
   }
 
   SetVisibility(delegate->IsCursorVisible(), delegate);
   NotifyMouseEventsEnableStateChange(enabled);
 }
 
 }  // namespace ash