Relocate reuseable portions of ash/display/display_util.*

ash/display/display_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_DISPLAY_MANAGER_H_
 #define ASH_DISPLAY_DISPLAY_MANAGER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 324 matching lines @@
       aura::Window* drag_source) const;
 
   // Create a screen instance to be used during shutdown.
   void CreateScreenForShutdown() const;
 
   // A unit test may change the internal display id (which never happens on
   // a real device). This will update the mode list for internal display
   // for this test scenario.
   void UpdateInternalManagedDisplayModeListForTest();
 
+  // Zoom the internal display.
+  bool ZoomInternalDisplay(bool up);
+
+  // Reset the internal display zoom.
+  void ResetInternalDisplayZoom();
+
  private:
   FRIEND_TEST_ALL_PREFIXES(ExtendedDesktopTest, ConvertPoint);
   FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest, TestNativeDisplaysChanged);
   FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest,
                            NativeDisplaysChangedAfterPrimaryChange);
   FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest, AutomaticOverscanInsets);
   FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest, Rotate);
   friend class AcceleratorControllerTest;
   friend class DisplayManagerTest;
   friend class chromeos::DisplayNotificationsTest;
@@ skipping 117 matching lines @@
   bool unified_desktop_enabled_;
 
   base::WeakPtrFactory<DisplayManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DISPLAY_DISPLAY_MANAGER_H_