Fix expected PlacementList sort order.

ui/display/manager/display_manager_utilities.h

 // Copyright 2016 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.
 
 #ifndef UI_DISPLAY_MANAGER_DISPLAY_MANAGER_UTILITIES_H_
 #define UI_DISPLAY_MANAGER_DISPLAY_MANAGER_UTILITIES_H_
 
 #include <set>
 
 #include "ui/display/display.h"
@@ skipping 72 matching lines @@
   SortDisplayIdList(&list);
   return list;
 }
 
 // Creates sorted DisplayIdList.
 DISPLAY_MANAGER_EXPORT DisplayIdList CreateDisplayIdList(const Displays& list);
 
 DISPLAY_MANAGER_EXPORT std::string DisplayIdListToString(
     const DisplayIdList& list);
 
-// Returns true if one of following conditions is met.
-// 1) id1 is internal.
-// 2) output index of id1 < output index of id2 and id2 isn't internal.
-DISPLAY_MANAGER_EXPORT bool CompareDisplayIds(int64_t id1, int64_t id2);
-
 }  // namespace display
 
 #endif  // UI_DISPLAY_MANAGER_DISPLAY_MANAGER_UTILITIES_H_