Makes Ctrl-Shift-L work in AppList

ash/shell_delegate.h

Index: ash/shell_delegate.h
diff --git a/ash/shell_delegate.h b/ash/shell_delegate.h
index ff60e8ac8275ebe864aa87b45d6812496b6894db..dd22e40c367d8b05dfc7be5de2696d0efcdf7fbc 100644
--- a/ash/shell_delegate.h
+++ b/ash/shell_delegate.h
@@ -56,6 +56,11 @@ class ASH_EXPORT ShellDelegate {
   // Invoked to create a new status area. Can return NULL.
   virtual views::Widget* CreateStatusArea() = 0;
 
+#if defined(OS_CHROMEOS)
+  // Invoked when a user uses Ctrl-Shift-L to lock the screen.
+  virtual void LockScreen() = 0;
+#endif
+
   // Invoked to ask the delegate to populate the |model|.
   virtual void BuildAppListModel(AppListModel* model) = 0;