Fix for Ash shortcuts unexpectedly working in system model dialog

ash/accelerators/accelerator_table.h

Index: ash/accelerators/accelerator_table.h
diff --git a/ash/accelerators/accelerator_table.h b/ash/accelerators/accelerator_table.h
index 14b43279fb44414cfc5061368fb0074c15c75098..54c5d4381d175063a0ce2a36eef1f89749e6a30b 100644
--- a/ash/accelerators/accelerator_table.h
+++ b/ash/accelerators/accelerator_table.h
@@ -136,6 +136,12 @@ ASH_EXPORT extern const AcceleratorAction kActionsAllowedAtLockScreen[];
 // The number of elements in kActionsAllowedAtLockScreen.
 ASH_EXPORT extern const size_t kActionsAllowedAtLockScreenLength;
 
+// Actions allowed while a modal window is up.
+ASH_EXPORT extern const AcceleratorAction kActionsAllowedAtModalWindow[];
+
+// The number of elements in kActionsAllowedAtModalWindow.
+ASH_EXPORT extern const size_t kActionsAllowedAtModalWindowLength;
+
 }  // namespace ash
 
 #endif  // ASH_ACCELERATORS_ACCELERATOR_TABLE_H_