Remove unused BluetoothClassicMedium::Observer.

PiperOrigin-RevId: 953415728

internal/platform/implementation/windows/bluetooth_classic_medium.cc

@@ -701,9 +701,6 @@ winrt::fire_and_forget BluetoothClassicMedium::DeviceWatcher_Added(
   if (discovery_callback_.device_discovered_cb != nullptr) {
     discovery_callback_.device_discovered_cb(*device);
   }
-  for (auto& observer : observers_.GetObservers()) {
-    observer->DeviceAdded(*device);
-  }
   return winrt::fire_and_forget();
 }
 
@@ -769,9 +766,6 @@ winrt::fire_and_forget BluetoothClassicMedium::DeviceWatcher_Updated(
     LOG(INFO) << __func__
               << ": Notifying device paired changed: " << std::boolalpha
               << new_paired_status;
-    for (auto& observer : observers_.GetObservers()) {
-      observer->DevicePairedChanged(*device, new_paired_status);
-    }
   }
 
   return winrt::fire_and_forget();
@@ -819,10 +813,6 @@ winrt::fire_and_forget BluetoothClassicMedium::DeviceWatcher_Removed(
     discovery_callback_.device_lost_cb(*device);
   }
 
-  for (auto& observer : observers_.GetObservers()) {
-    observer->DeviceRemoved(*device);
-  }
-
   RemoveRemoteDevice(mac_address);
 
   return winrt::fire_and_forget();

internal/platform/implementation/windows/bluetooth_classic_medium.h

@@ -21,7 +21,6 @@
 #include "absl/base/thread_annotations.h"
 #include "absl/container/flat_hash_map.h"
 #include "absl/synchronization/mutex.h"
-#include "internal/base/observer_list.h"
 #include "internal/platform/cancellation_flag.h"
 #include "internal/platform/implementation/bluetooth_adapter.h"
 #include "internal/platform/implementation/bluetooth_classic.h"
@@ -90,15 +89,6 @@ class BluetoothClassicMedium : public api::BluetoothClassicMedium {
   std::unique_ptr<api::BluetoothPairing> CreatePairing(
       api::BluetoothDevice& remote_device) override;
 
-  void AddObserver(Observer* observer) override {
-    observers_.AddObserver(observer);
-  }
-
-  // Removes an observer. It's OK to remove an unregistered observer.
-  void RemoveObserver(Observer* observer) override {
-    observers_.RemoveObserver(observer);
-  }
-
  private:
   bool StartScanning();
   bool StopScanning();
@@ -191,7 +181,6 @@ class BluetoothClassicMedium : public api::BluetoothClassicMedium {
   // the shared_ptr.
   BluetoothServerSocket* raw_server_socket_ = nullptr;
   bool is_radio_discoverable_ = false;
-  ObserverList<Observer> observers_;
 };
 
 }  // namespace nearby::windows

internal/platform/implementation/windows/mutex.h

@@ -19,6 +19,7 @@
 
 #include "absl/synchronization/mutex.h"
 #include "internal/platform/implementation/mutex.h"
+#include "internal/platform/condition_variable.h"
 
 namespace nearby {
 namespace windows {