Fixes for -Wunused-function on Linux, Android and ChromeOS

ash/wm/lock_state_controller_unittest.cc

 // Copyright 2013 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.
 
 #include "ash/wm/lock_state_controller.h"
 
 #include "ash/ash_switches.h"
 #include "ash/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
@@ skipping 37 matching lines @@
 aura::Window* GetContainer(int container ) {
   aura::Window* root_window = Shell::GetPrimaryRootWindow();
   return Shell::GetContainer(root_window, container);
 }
 
 bool IsBackgroundHidden() {
   return !GetContainer(internal::kShellWindowId_DesktopBackgroundContainer)->
               IsVisible();
 }
 
-void ShowBackground() {
-  ui::ScopedLayerAnimationSettings settings(
-      GetContainer(internal::kShellWindowId_DesktopBackgroundContainer)->
-          layer()->GetAnimator());
-  settings.SetTransitionDuration(base::TimeDelta());
-  GetContainer(internal::kShellWindowId_DesktopBackgroundContainer)->Show();
-}
-
 void HideBackground() {
   ui::ScopedLayerAnimationSettings settings(
       GetContainer(internal::kShellWindowId_DesktopBackgroundContainer)->
           layer()->GetAnimator());
   settings.SetTransitionDuration(base::TimeDelta());
   GetContainer(internal::kShellWindowId_DesktopBackgroundContainer)->Hide();
 }
 
 } // namespace
 
@@ skipping 979 matching lines @@
 
   Advance(SessionStateAnimator::ANIMATION_SPEED_MOVE_WINDOWS);
   ExpectUnlockAfterUIDestroyedAnimationFinished();
   EXPECT_TRUE(IsBackgroundHidden());
 
   ExpectUnlockedState();
 }
 
 }  // namespace test
 }  // namespace ash