Fix bug 145175: [Win] Frameless app windows are not resizable if no draggable region is specified
This happens because RWHV is created for the new RVH instead of the existing RVH associated with the web contents when navigating a web contents to extension URL (see http://crbug.com/123007
). When ShellWindowViews tries to set the clickthrough region for resizing purpose, it fails due to no RWHV for the existing RVH. The fix is to make the native window do it again when RWHV is available after RVH is updated.
TEST=Manual test by launching and resizing frameless window without draggable region specified