chromeos: Remove AshTestBase::SupportsMultipleDisplays

ash/common/test/ash_test.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 ASH_COMMON_TEST_ASH_TEST_H_
 #define ASH_COMMON_TEST_ASH_TEST_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 55 matching lines @@
   ~AshTest() override;
 
   // Returns the WmShelf for the primary display.
   static WmShelf* GetPrimaryShelf();
 
   // Returns the system tray on the primary display.
   static SystemTray* GetPrimarySystemTray();
 
   static test::TestSystemTrayDelegate* GetSystemTrayDelegate();
 
-  bool SupportsMultipleDisplays() const;
-
   // Update the display configuration as given in |display_spec|.
   // See test::DisplayManagerTestApi::UpdateDisplay for more details.
   void UpdateDisplay(const std::string& display_spec);
 
   // Creates a visible window in the appropriate container. If
   // |bounds_in_screen| is empty the window is added to the primary root
   // window, otherwise the window is added to the display matching
   // |bounds_in_screen|. |shell_window_id| is the shell window id to give to
   // the new window.
   std::unique_ptr<WindowOwner> CreateTestWindow(
@@ skipping 54 matching lines @@
 
  private:
   std::unique_ptr<AshTestImpl> test_impl_;
 
   DISALLOW_COPY_AND_ASSIGN(AshTest);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_TEST_ASH_TEST_H_