Implement BluetoothRemoteGattCharacteristicWin::StartNotifySession and related unit tests

device/bluetooth/bluetooth_remote_gatt_characteristic_win.h

Index: device/bluetooth/bluetooth_remote_gatt_characteristic_win.h
diff --git a/device/bluetooth/bluetooth_remote_gatt_characteristic_win.h b/device/bluetooth/bluetooth_remote_gatt_characteristic_win.h
index bf37ccc17e8a470acdf7a2c495b9173f4358a1ed..2d984c23dd65e27a1313c21c254dd6357c137aac 100644
--- a/device/bluetooth/bluetooth_remote_gatt_characteristic_win.h
+++ b/device/bluetooth/bluetooth_remote_gatt_characteristic_win.h
@@ -52,10 +52,14 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothRemoteGattCharacteristicWin
                                  const base::Closure& callback,
                                  const ErrorCallback& error_callback) override;
 
+  // Handles Bluetooth LE GATT event from OS.
+  void OnGetRemoteGattEvent(BTH_LE_GATT_EVENT_TYPE type, PVOID event_parameter);
+
   // Update included descriptors.
   void Update();
   uint16_t GetAttributeHandle() const;
   BluetoothRemoteGattServiceWin* GetWinService() { return parent_service_; }
+  void StopNotifySession();
 
  private:
   void OnGetIncludedDescriptorsCallback(
@@ -80,6 +84,10 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothRemoteGattCharacteristicWin
       HRESULT hr);
   void OnWriteRemoteCharacteristicValueCallback(HRESULT hr);
   BluetoothGattService::GattErrorCode HRESULTToGattErrorCode(HRESULT hr);
+  void OnGattCharacteristicValueChanged(scoped_ptr<uint8_t> new_value,
+                                        ULONG size);
+  void GattEventRegistrationCallback(BLUETOOTH_GATT_EVENT_HANDLE event_handle,
+                                     HRESULT hr);
 
   BluetoothRemoteGattServiceWin* parent_service_;
   scoped_refptr<BluetoothTaskManagerWin> task_manager_;
@@ -110,6 +118,18 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothRemoteGattCharacteristicWin
 
   bool characteristic_value_read_or_write_in_progress_;
 
+  unsigned int number_of_active_notify_sessions_;
+
+  // Vector stores StartNotifySession request callbacks.
+  std::vector<std::pair<NotifySessionCallback, ErrorCallback>>
+      start_notify_session_callbacks_;
+
+  // Flag indicates if GATT event registration is in progress.
+  bool gatt_event_registeration_in_progress_;
+
+  // GATT event handle from OS.
+  BLUETOOTH_GATT_EVENT_HANDLE gatt_event_handle_;
+
   base::WeakPtrFactory<BluetoothRemoteGattCharacteristicWin> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(BluetoothRemoteGattCharacteristicWin);
 };