The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0f6d2799e18907d3419645099fd9b920318f5310

commit 0f6d2799e18907d3419645099fd9b920318f5310
Author: juncai <juncai@chromium.org>
Date: Wed Nov 23 18:38:07 2016

Add multiple selection support to chooser on desktops

This CL is part 1 of changing Chrome Apps device permissions dialog
using the same chooser dialog as WebUSB and WebBluetooth. Since the
device permissions dialog allows multiple selection, this CL added code
to support multiple selection for chooser.

BUG= 653222 

Review-Url: https://codereview.chromium.org/2518933004
Cr-Commit-Position: refs/heads/master@{#434209}

[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/chooser_controller/chooser_controller.cc
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/chooser_controller/chooser_controller.h
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/chooser_controller/mock_chooser_controller.h
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/ui/bluetooth/bluetooth_chooser_controller.cc
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/ui/bluetooth/bluetooth_chooser_controller_unittest.cc
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/ui/cocoa/chooser_content_view_cocoa.mm
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/ui/cocoa/extensions/chooser_dialog_cocoa_controller_unittest.mm
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/ui/views/chooser_content_view.cc
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/usb/usb_chooser_controller.cc
[modify] https://crrev.com/0f6d2799e18907d3419645099fd9b920318f5310/chrome/browser/usb/usb_chooser_controller.h