Made ble_v2_medium and bluetooth_classic_medium share a devices_

internal/platform/implementation/linux/bluetooth_classic_medium.cc

@@ -34,16 +34,21 @@
 
 namespace nearby {
 namespace linux {
-BluetoothClassicMedium::BluetoothClassicMedium(BluetoothAdapter &adapter)
-    : system_bus_(adapter.GetConnection()),
-      adapter_(adapter),
-      observers_(std::make_shared<ObserverList<Observer>>()),
-      devices_(std::make_shared<BluetoothDevices>(
-          system_bus_, adapter.GetObjectPath(), *observers_)),
-      device_watcher_(nullptr),
-      // agent_manager_(std::make_unique<AgentManager>(*system_bus_)),
-      profile_manager_(
-          std::make_unique<ProfileManager>(*system_bus_, *devices_)) {}
+BluetoothClassicMedium::BluetoothClassicMedium(BluetoothAdapter &adapter)
+    : system_bus_(adapter.GetConnection()),
+      adapter_(adapter),
+      observers_(nullptr),
+      devices_(nullptr),
+      device_watcher_(nullptr),
+      // agent_manager_(std::make_unique<AgentManager>(*system_bus_)),
+      profile_manager_(nullptr) {
+  auto shared =
+      GetSharedBluetoothDevices(system_bus_, adapter_.GetObjectPath());
+  observers_ = shared->observers;
+  devices_ = shared->devices;
+  profile_manager_ =
+      std::make_unique<ProfileManager>(*system_bus_, *devices_);
+}
 
 bool BluetoothClassicMedium::StartDiscovery(
     DiscoveryCallback discovery_callback) {
@@ -160,6 +165,7 @@ BluetoothClassicMedium::ListenForService(const std::string &service_name,
 
 api::BluetoothDevice *BluetoothClassicMedium::GetRemoteDevice(
 MacAddress mac_address) {
+  // When BLE is discovering, it looks for remote devices to connect to using BT classic. If only
   auto device = devices_->get_device_by_address(mac_address.ToString());
   if (device == nullptr) return nullptr;