Add window states docked; and docked minimized. Add wm window event to set docked and undocked.

ash/wm/maximize_mode/maximize_mode_window_state.cc

Index: ash/wm/maximize_mode/maximize_mode_window_state.cc
diff --git a/ash/wm/maximize_mode/maximize_mode_window_state.cc b/ash/wm/maximize_mode/maximize_mode_window_state.cc
index e30c4b1878a05804808da4e901fbfcb4a0913d9e..c11a2c318d96945402b435cb4b5d77e6fc4cb500 100644
--- a/ash/wm/maximize_mode/maximize_mode_window_state.cc
+++ b/ash/wm/maximize_mode/maximize_mode_window_state.cc
@@ -132,6 +132,7 @@ void MaximizeModeWindowState::OnWMEvent(wm::WindowState* window_state,
     case wm::WM_EVENT_SNAP_RIGHT:
     case wm::WM_EVENT_NORMAL:
     case wm::WM_EVENT_MAXIMIZE:
+    case wm::WM_EVENT_DOCK:
       UpdateWindow(window_state,
                    GetMaximizedOrCenteredWindowType(window_state),
                    true);