Removes some dead code

ash/display/window_tree_host_manager.h

 // 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.
 
 #ifndef ASH_DISPLAY_WINDOW_TREE_HOST_MANAGER_H_
 #define ASH_DISPLAY_WINDOW_TREE_HOST_MANAGER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 139 matching lines @@
 
   // aura::WindowTreeHostObserver overrides:
   void OnHostResized(const aura::WindowTreeHost* host) override;
 
   // display::DisplayManager::Delegate overrides:
   void CreateOrUpdateMirroringDisplay(
       const display::DisplayInfoList& info_list) override;
   void CloseMirroringDisplayIfNotNecessary() override;
   void PreDisplayConfigurationChange(bool clear_focus) override;
   void PostDisplayConfigurationChange(bool must_clear_window) override;
-#if defined(OS_CHROMEOS)
   ui::DisplayConfigurator* display_configurator() override;
-#endif
 
   // ui::internal::InputMethodDelegate overrides:
   ui::EventDispatchDetails DispatchKeyEventPostIME(
       ui::KeyEvent* event) override;
 
   InputMethodEventHandler* input_method_event_handler() {
     return input_method_event_handler_.get();
   }
 
  private:
   FRIEND_TEST_ALL_PREFIXES(WindowTreeHostManagerTest, BoundsUpdated);
   FRIEND_TEST_ALL_PREFIXES(WindowTreeHostManagerTest, SecondaryDisplayLayout);
-  friend class DisplayManager;
   friend class MirrorWindowController;
 
   // Creates a WindowTreeHost for |display| and stores it in the
   // |window_tree_hosts_| map.
   AshWindowTreeHost* AddWindowTreeHostForDisplay(
       const display::Display& display,
       const AshWindowTreeHostInitParams& params);
 
   // Delete the AsWindowTreeHost. This does not remove the entry from
   // |window_tree_hosts_|. Caller has to explicitly remove it.
@@ skipping 29 matching lines @@
   int64_t cursor_display_id_for_restore_;
 
   base::WeakPtrFactory<WindowTreeHostManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DISPLAY_WINDOW_TREE_HOST_MANAGER_H_