Implement WebBluetooth getDescriptor[s]

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

Index: third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.h
diff --git a/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.h b/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.h
index 9d085bce3825fefa469d854dd2ed0abacbcf1dce..31ec02ec367d1bba368423fb903963ae8dd542c2 100644
--- a/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.h
+++ b/third_party/WebKit/Source/modules/bluetooth/BluetoothDevice.h
@@ -19,12 +19,14 @@ namespace blink {
 
 class BluetoothAttributeInstanceMap;
 class BluetoothRemoteGATTCharacteristic;
+class BluetoothRemoteGATTDescriptor;
 class BluetoothRemoteGATTServer;
 class BluetoothRemoteGATTService;
 class ScriptPromise;
 class ScriptPromiseResolver;
 
 struct WebBluetoothRemoteGATTCharacteristicInit;
+struct WebBluetoothRemoteGATTDescriptorInit;
 struct WebBluetoothRemoteGATTService;
 
 // BluetoothDevice represents a physical bluetooth device in the DOM. See IDL.
@@ -59,6 +61,11 @@ class BluetoothDevice final : public EventTargetWithInlineData,
       BluetoothRemoteGATTService*);
   bool isValidCharacteristic(const String& characteristicInstanceId);
 
+  BluetoothRemoteGATTDescriptor* getOrCreateBluetoothRemoteGATTDescriptor(
+      std::unique_ptr<WebBluetoothRemoteGATTDescriptorInit>,
+      BluetoothRemoteGATTCharacteristic*);
+  bool isValidDescriptor(const String& descriptorInstanceId);
+
   // We should disconnect from the device in all of the following cases:
   // 1. When the object gets GarbageCollected e.g. it went out of scope.
   // dispose() is called in this case.