bluetooth: Refactor (Add|Remove)Observer impls into BluetoothAdapter.

device/bluetooth/bluetooth_adapter.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "device/bluetooth/bluetooth_adapter.h"
 
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "device/bluetooth/bluetooth_discovery_session.h"
@@ skipping 16 matching lines @@
 base::WeakPtr<BluetoothAdapter> BluetoothAdapter::GetWeakPtrForTesting() {
   return weak_ptr_factory_.GetWeakPtr();
 }
 
 #if defined(OS_CHROMEOS)
 void BluetoothAdapter::Shutdown() {
   NOTIMPLEMENTED();
 }
 #endif
 
+void BluetoothAdapter::AddObserver(BluetoothAdapter::Observer* observer) {
+  DCHECK(observer);
+  observers_.AddObserver(observer);
+}
+
+void BluetoothAdapter::RemoveObserver(BluetoothAdapter::Observer* observer) {
+  DCHECK(observer);
+  observers_.RemoveObserver(observer);
+}
+
 void BluetoothAdapter::StartDiscoverySession(
     const DiscoverySessionCallback& callback,
     const ErrorCallback& error_callback) {
   StartDiscoverySessionWithFilter(nullptr, callback, error_callback);
 }
 
 void BluetoothAdapter::StartDiscoverySessionWithFilter(
     scoped_ptr<BluetoothDiscoveryFilter> discovery_filter,
     const DiscoverySessionCallback& callback,
     const ErrorCallback& error_callback) {
@@ skipping 159 matching lines @@
       continue;
     }
 
     result = BluetoothDiscoveryFilter::Merge(result.get(), curr_filter);
   }
 
   return result.Pass();
 }
 
 }  // namespace device