mash: Migrate ShelfLockingManager to ash/common.

chrome/browser/chromeos/login/lock/webui_screen_locker.cc

Index: chrome/browser/chromeos/login/lock/webui_screen_locker.cc
diff --git a/chrome/browser/chromeos/login/lock/webui_screen_locker.cc b/chrome/browser/chromeos/login/lock/webui_screen_locker.cc
index 83bdcb2f63fa811061cae91f83570f71c1597335..409da2e55ef5ae135d2141c13fa346c69926cf6c 100644
--- a/chrome/browser/chromeos/login/lock/webui_screen_locker.cc
+++ b/chrome/browser/chromeos/login/lock/webui_screen_locker.cc
@@ -7,8 +7,6 @@
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/system/chromeos/power/power_event_observer.h"
-#include "ash/wm/lock_state_controller.h"
-#include "ash/wm/lock_state_observer.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
@@ -67,7 +65,7 @@ WebUIScreenLocker::WebUIScreenLocker(ScreenLocker* screen_locker)
       network_state_helper_(new login::NetworkStateHelper),
       weak_factory_(this) {
   set_should_emit_login_prompt_visible(false);
-  ash::Shell::GetInstance()->lock_state_controller()->AddObserver(this);
+  ash::WmShell::Get()->AddLockStateObserver(this);
   ash::WmShell::Get()->AddShellObserver(this);
   display::Screen::GetScreen()->AddObserver(this);
   DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(this);
@@ -166,8 +164,7 @@ void WebUIScreenLocker::ResetAndFocusUserPod() {
 WebUIScreenLocker::~WebUIScreenLocker() {
   DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(this);
   display::Screen::GetScreen()->RemoveObserver(this);
-  ash::Shell::GetInstance()->lock_state_controller()->RemoveObserver(this);
-
+  ash::WmShell::Get()->RemoveLockStateObserver(this);
   ash::WmShell::Get()->RemoveShellObserver(this);
   // In case of shutdown, lock_window_ may be deleted before WebUIScreenLocker.
   if (lock_window_) {