bluetooth: Improve error message for retrieving Descriptors when disconnecting

third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-device-disconnects-before.js

Index: third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-device-disconnects-before.js
diff --git a/third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-device-disconnects-before.js b/third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-device-disconnects-before.js
new file mode 100644
index 0000000000000000000000000000000000000000..5aae9be03d00af62cb39d3255ff8b556eb422314
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-device-disconnects-before.js
@@ -0,0 +1,28 @@
+'use strict';
+promise_test(() => {
+  let val = new Uint8Array([1]);
+  return setBluetoothFakeAdapter('DisconnectingHealthThermometerAdapter')
+      .then(() => requestDeviceWithKeyDown({
+              filters: [{services: ['health_thermometer']}],
+              optionalServices: [request_disconnection_service_uuid]
+            }))
+      .then(device => device.gatt.connect())
+      .then(gattServer => {
+        let measurement_interval;
+        return gattServer.getPrimaryService('health_thermometer')
+            .then(ht => ht.getCharacteristic('measurement_interval'))
+            .then(mi => measurement_interval = mi)
+            .then(() => get_request_disconnection(gattServer))
+            .then(requestDisconnection => requestDisconnection())
+            .then(
+                () => assert_promise_rejects_with_message(
+                    measurement_interval.CALLS(
+                        [getDescriptor(user_description.name) |
+                         getDescriptors(user_description.name)[UUID] |
+                         getDescriptors()]),
+                    new DOMException(
+                        'GATT Server is disconnected. Cannot retrieve descriptors. ' +
+                            '(Re)connect first with `device.gatt.connect`.',
+                        'NetworkError')));
+      });
+}, 'Device disconnects before FUNCTION_NAME. Reject with NetworkError.');