Merge pull request #333 from reillyeon/device-info

usb_device-info: Handle the case of a device being selected again.
Don't disconnect same device of GATT services
Merge pull request #334 from oahziur/ble

 bluetooth-samples_heart-rate-sensor: Don't disconnect same device of GATT services
Add Chrome OS support for the USB Device Info app.

On Chrome OS chrome.usb.requestAccess must be called before the device
can be opened. Some adjustments to the CSS also had to be made due to
differences in the size of input elements between platforms.