Allow Control+Shift+Q on lock screen.

ash/accelerators/accelerator_controller.h

Index: ash/accelerators/accelerator_controller.h
diff --git a/ash/accelerators/accelerator_controller.h b/ash/accelerators/accelerator_controller.h
index df474275684fa797136c3b5ad5fbe315a9e0b03a..96601076f0f009c317ca8c2fc626e6efe5b9b27b 100644
--- a/ash/accelerators/accelerator_controller.h
+++ b/ash/accelerators/accelerator_controller.h
@@ -103,8 +103,10 @@ class ASH_EXPORT AcceleratorController : public ui::AcceleratorTarget {
   // the implementation.
   std::map<ui::Accelerator, int> accelerators_;
 
-  // Actions allowed when the user is not signed in or screen is locked
+  // Actions allowed when the user is not signed in.
   std::set<int> actions_allowed_at_login_screen_;
+  // Actions allowed when the screen is locked.
+  std::set<int> actions_allowed_at_lock_screen_;
 
   DISALLOW_COPY_AND_ASSIGN(AcceleratorController);
 };