Implement WebBluetooth getDescriptor[s]

third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-out-of-range.js

+'use strict';
+promise_test(() => {

[ortuno, 2016/12/07 08:05:12]

I think this should be called 'devices-goes-out-of-range.js' with a TODO to use
this for the rest characteristic's functions.

+  return setBluetoothFakeAdapter('DisconnectingHealthThermometerAdapter')
+    .then(() => requestDeviceWithKeyDown({
+      filters: [{services: ['health_thermometer']}],
+      optionalServices: ['generic_access']}))

[ortuno, 2016/12/07 08:05:13]

no need for generic access.

[dougt, 2016/12/07 19:48:57]

Done.

+    .then(device => device.gatt.connect())
+    .then(gattServer => gattServer.getPrimaryService('health_thermometer'))
+    .then(service => service.getCharacteristic('measurement_interval'))
+    .then(characteristic =>
+    {

[ortuno, 2016/12/07 08:05:13]

nit: move to line above

[dougt, 2016/12/07 19:48:57]

Done.

+      return setBluetoothFakeAdapter('EmptyAdapter')
+        .then(() => assert_promise_rejects_with_message(
+          characteristic.CALLS([
+            getDescriptor(user_description.name)|
+            getDescriptors(user_description.name)]),
+          new DOMException('Bluetooth Device is no longer in range.',
+                           'NetworkError'),
+        'Device went out of range.'));
+    });
+}, 'Device goes out of range. Reject with NetworkError.');