bluetooth: BluetoothAdapterDeleter used to control BluetoothAdapter destruction.

device/bluetooth/bluetooth_adapter_chromeos.h

Index: device/bluetooth/bluetooth_adapter_chromeos.h
diff --git a/device/bluetooth/bluetooth_adapter_chromeos.h b/device/bluetooth/bluetooth_adapter_chromeos.h
index 30deae6d8cec00ce23faf0a2ab8e1fe225947b43..0bcd6f741fe3e52368fa1ce2f421971f3a3d8057 100644
--- a/device/bluetooth/bluetooth_adapter_chromeos.h
+++ b/device/bluetooth/bluetooth_adapter_chromeos.h
@@ -44,6 +44,7 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapterChromeOS
   static base::WeakPtr<BluetoothAdapter> CreateAdapter();
 
   // BluetoothAdapter:
+  void DeleteOnCorrectThread() const override;
   virtual void AddObserver(
       device::BluetoothAdapter::Observer* observer) override;
   virtual void RemoveObserver(
@@ -116,6 +117,7 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapterChromeOS
       device::BluetoothDevice::PairingDelegate* pairing_delegate) override;
 
  private:
+  friend class base::DeleteHelper<BluetoothAdapterChromeOS>;
   friend class BluetoothChromeOSTest;
 
   // typedef for callback parameters that are passed to AddDiscoverySession