Makes WorkspaceLayoutManager use ash/wm/common types

ash/wm/aura/wm_globals_aura.cc

Index: ash/wm/aura/wm_globals_aura.cc
diff --git a/ash/wm/aura/wm_globals_aura.cc b/ash/wm/aura/wm_globals_aura.cc
index 2d2d455da07f51aef421a8fbde871635ce5a416c..7de57d99fdfb5a85129734278baa3529482be4b4 100644
--- a/ash/wm/aura/wm_globals_aura.cc
+++ b/ash/wm/aura/wm_globals_aura.cc
@@ -89,6 +89,10 @@ bool WmGlobalsAura::IsForceMaximizeOnFirstRun() {
   return Shell::GetInstance()->delegate()->IsForceMaximizeOnFirstRun();
 }
 
+bool WmGlobalsAura::IsScreenLocked() {
+  return Shell::GetInstance()->session_state_delegate()->IsScreenLocked();
+}
+
 void WmGlobalsAura::LockCursor() {
   ash::Shell::GetInstance()->cursor_manager()->LockCursor();
 }