Save and restore State for ShellWindows, including panels

ui/base/ui_base_types.h

Index: ui/base/ui_base_types.h
diff --git a/ui/base/ui_base_types.h b/ui/base/ui_base_types.h
index 3eb46cab373cef5c7dde433d7d27a1bbab4374bc..2f1bcec9eaed0d4ad9d7cdc2ad187538483f6c11 100644
--- a/ui/base/ui_base_types.h
+++ b/ui/base/ui_base_types.h
@@ -17,7 +17,8 @@ enum WindowShowState {
   SHOW_STATE_MAXIMIZED  = 3,
   SHOW_STATE_INACTIVE   = 4,  // Views only, not persisted.
   SHOW_STATE_FULLSCREEN = 5,
-  SHOW_STATE_END        = 6   // The end of show state enum.
+  SHOW_STATE_DETACHED   = 6,  // Views only; detached panel.
+  SHOW_STATE_END        = 7   // The end of show state enum.
 };
 
 // Dialog button identifiers used to specify which buttons to show the user.