Move more from WmShell to Shell

ash/root_window_controller_unittest.cc

Index: ash/root_window_controller_unittest.cc
diff --git a/ash/root_window_controller_unittest.cc b/ash/root_window_controller_unittest.cc
index cf5c9b90ba10b350705a2b986be9b06db502e323..d6eeb14546306d15bc5b19e1f37ba83b673af6ef 100644
--- a/ash/root_window_controller_unittest.cc
+++ b/ash/root_window_controller_unittest.cc
@@ -387,7 +387,7 @@ TEST_F(RootWindowControllerTest, ModalContainer) {
   WmShell* wm_shell = WmShell::Get();
   RootWindowController* controller = wm_shell->GetPrimaryRootWindowController();
   EXPECT_EQ(LoginStatus::USER,
-            wm_shell->system_tray_delegate()->GetUserLoginStatus());
+            Shell::Get()->system_tray_delegate()->GetUserLoginStatus());
   EXPECT_EQ(GetLayoutManager(controller, kShellWindowId_SystemModalContainer),
             controller->GetSystemModalLayoutManager(NULL));
 
@@ -399,7 +399,7 @@ TEST_F(RootWindowControllerTest, ModalContainer) {
 
   wm_shell->GetSessionStateDelegate()->LockScreen();
   EXPECT_EQ(LoginStatus::LOCKED,
-            wm_shell->system_tray_delegate()->GetUserLoginStatus());
+            Shell::Get()->system_tray_delegate()->GetUserLoginStatus());
   EXPECT_EQ(
       GetLayoutManager(controller, kShellWindowId_LockSystemModalContainer),
       controller->GetSystemModalLayoutManager(nullptr));
@@ -427,7 +427,7 @@ TEST_F(RootWindowControllerTest, ModalContainerNotLoggedInLoggedIn) {
       WmShell::Get()->GetSessionStateDelegate();
   SetUserLoggedIn(false);
   EXPECT_EQ(LoginStatus::NOT_LOGGED_IN,
-            WmShell::Get()->system_tray_delegate()->GetUserLoginStatus());
+            Shell::Get()->system_tray_delegate()->GetUserLoginStatus());
   EXPECT_EQ(0, session_state_delegate->NumberOfLoggedInUsers());
   EXPECT_FALSE(session_state_delegate->IsActiveUserSessionStarted());
 
@@ -451,7 +451,7 @@ TEST_F(RootWindowControllerTest, ModalContainerNotLoggedInLoggedIn) {
   SetUserLoggedIn(true);
   SetSessionStarted(true);
   EXPECT_EQ(LoginStatus::USER,
-            WmShell::Get()->system_tray_delegate()->GetUserLoginStatus());
+            Shell::Get()->system_tray_delegate()->GetUserLoginStatus());
   EXPECT_EQ(1, session_state_delegate->NumberOfLoggedInUsers());
   EXPECT_TRUE(session_state_delegate->IsActiveUserSessionStarted());
   EXPECT_EQ(GetLayoutManager(controller, kShellWindowId_SystemModalContainer),