ChooserBubbleController class is used by both WebUSB and WebBluetooth. As bug 577170 described, a chooser dialog needs to be implemented on Chrome Apps so that WebBluetooth API can be used there. And step one is to refactor ChooserBubbleController to be ChooserController and move it probably to //components/chooser_controller.
Comment 1 by bugdroid1@chromium.org
, May 27 2016