bluetooth: Improve error message for retrieving Descriptors when disconnecting

third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-disconnect-called-before.js

Index: third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-disconnect-called-before.js
diff --git a/third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-disconnect-called-before.js b/third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-disconnect-called-before.js
new file mode 100644
index 0000000000000000000000000000000000000000..fce3becaadeb4a2ce0b4a71d98d9e4bb03a8db15
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/bluetooth/script-tests/characteristic/descriptor-disconnect-called-before.js
@@ -0,0 +1,25 @@
+'use strict';
+promise_test(() => {
+  let val = new Uint8Array([1]);
+  return setBluetoothFakeAdapter('DisconnectingHealthThermometerAdapter')
+      .then(
+          () => requestDeviceWithKeyDown(
+              {filters: [{services: ['health_thermometer']}]}))
+      .then(device => device.gatt.connect())
+      .then(gattServer => {
+        return gattServer.getPrimaryService('health_thermometer')
+            .then(service => service.getCharacteristic('measurement_interval'))
+            .then(measurement_interval => {
+              gattServer.disconnect();
+              return 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'));
+            });
+      });
+}, 'disconnect() called before FUNCTION_NAME. Reject with NetworkError.');