[Clean up] Expose ConnectToServiceInsecurely as a BluetoothDevice API on all platforms.

components/proximity_auth/bluetooth_connection.h

Index: components/proximity_auth/bluetooth_connection.h
diff --git a/components/proximity_auth/bluetooth_connection.h b/components/proximity_auth/bluetooth_connection.h
index 8b09a6f6ab9fb82eb4911795d3f34c1475c7e88b..ebe4f8dd9b6f0ebd9ca3022660707b9946a68530 100644
--- a/components/proximity_auth/bluetooth_connection.h
+++ b/components/proximity_auth/bluetooth_connection.h
@@ -45,14 +45,6 @@ class BluetoothConnection : public Connection,
   virtual void DeviceRemoved(device::BluetoothAdapter* adapter,
                              device::BluetoothDevice* device) override;
 
-  // Exposed for testing.
-  virtual void ConnectToService(
-      device::BluetoothDevice* device,
-      const device::BluetoothUUID& uuid,
-      const device::BluetoothDevice::ConnectToServiceCallback& callback,
-      const device::BluetoothDevice::ConnectToServiceErrorCallback&
-          error_callback);
-
  private:
   // Registers receive callbacks with the backing |socket_|.
   void StartReceive();