Implement WebBluetooth getDescriptor[s]

third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.cpp

Index: third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.cpp
diff --git a/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.cpp b/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.cpp
index edf8326abf33722fa21ff893961af5ea1d5c2988..718a9e45fca3fac0078728835b16dae6d45806ec 100644
--- a/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.cpp
+++ b/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.cpp
@@ -63,6 +63,14 @@ bool BluetoothDevice::isValidCharacteristic(
       characteristicInstanceId);
 }
 
+BluetoothRemoteGATTDescriptor*
+BluetoothDevice::getOrCreateBluetoothRemoteGATTDescriptor(
+    std::unique_ptr<WebBluetoothRemoteGATTDescriptorInit> webDescriptor,
+    BluetoothRemoteGATTCharacteristic* characteristic) {
+  return m_attributeInstanceMap->getOrCreateBluetoothRemoteGATTDescriptor(
+      std::move(webDescriptor), characteristic);
+}
+
 void BluetoothDevice::dispose() {
   disconnectGATTIfConnected();
 }