mash: Migrate shelf app list button to wm common types

ash/wm/window_cycle_controller_unittest.cc

Index: ash/wm/window_cycle_controller_unittest.cc
diff --git a/ash/wm/window_cycle_controller_unittest.cc b/ash/wm/window_cycle_controller_unittest.cc
index e1b1c5867f2364f199228e9378017944a36b25d2..21f02e37d20cfee4b5545a1d570c28d8446c7416 100644
--- a/ash/wm/window_cycle_controller_unittest.cc
+++ b/ash/wm/window_cycle_controller_unittest.cc
@@ -486,10 +486,10 @@ TEST_F(WindowCycleControllerTest, SelectingHidesAppList) {
 
   std::unique_ptr<aura::Window> window0(CreateTestWindowInShellWithId(0));
   std::unique_ptr<aura::Window> window1(CreateTestWindowInShellWithId(1));
-  Shell::GetInstance()->ShowAppList(NULL);
-  EXPECT_TRUE(Shell::GetInstance()->GetAppListTargetVisibility());
+  WmShell::Get()->ShowAppList();
+  EXPECT_TRUE(WmShell::Get()->GetAppListTargetVisibility());
   controller->HandleCycleWindow(WindowCycleController::FORWARD);
-  EXPECT_FALSE(Shell::GetInstance()->GetAppListTargetVisibility());
+  EXPECT_FALSE(WmShell::Get()->GetAppListTargetVisibility());
 }
 
 // Tests that cycling through windows shows and minimizes windows as they