Remove some ifdefs from ash since it only supports ChromeOS now.

ash/display/display_util.h

 // Copyright 2014 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_UTIL_H_
 #define ASH_DISPLAY_DISPLAY_UTIL_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 18 matching lines @@
 
 // Creates a MouseWarpController for the current display
 // configuration. |drag_source| is the window where dragging
 // started, or nullptr otherwise.
 std::unique_ptr<MouseWarpController> CreateMouseWarpController(
     display::DisplayManager* manager,
     aura::Window* drag_source);
 
 // Creates edge bounds from |bounds_in_screen| that fits the edge
 // of the native window for |ash_host|.
 ASH_EXPORT gfx::Rect GetNativeEdgeBounds(AshWindowTreeHost* ash_host,

[Evan Stade, 2017/01/13 17:19:34]

I don't actually know why these EXPORTs are necessary. The exported functions
are used by ash_unittests, and yet when I remove the exports it still works
(even a component build). Do unit tests have always link statically or
something?

[James Cook, 2017/01/13 20:19:31]

Huh. I thought they were necessary for unit tests too. If it works with
component build, and it passes on the bots, feel free to remove them. Or leave
them, I don't feel strongly.

                                          const gfx::Rect& bounds_in_screen);
 
 // Moves the cursor to the point inside the |ash_host| that is closest to
 // the point_in_screen, which may be outside of the root window.
 // |update_last_loation_now| is used for the test to update the mouse
 // location synchronously.
 void MoveCursorTo(AshWindowTreeHost* ash_host,
                   const gfx::Point& point_in_screen,
                   bool update_last_location_now);
 
-#if defined(OS_CHROMEOS)
 // Shows the notification message for display related issues, and optionally
 // adds a button to send a feedback report.
 void ShowDisplayErrorNotification(const base::string16& message,
                                   bool allow_feedback);
-#endif
 
 ASH_EXPORT base::string16 GetDisplayErrorNotificationMessageForTest();
 
 }  // namespace ash
 
 #endif  // ASH_DISPLAY_DISPLAY_UTIL_H_