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

device/bluetooth/bluetooth_adapter_mac.mm

 // Copyright 2013 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_mac.h"
 
 #import <IOBluetooth/objc/IOBluetoothDevice.h>
 #import <IOBluetooth/objc/IOBluetoothHostController.h>
 
 #include <string>
@@ skipping 46 matching lines @@
       num_discovery_sessions_(0),
       classic_discovery_manager_(
           BluetoothDiscoveryManagerMac::CreateClassic(this)),
       weak_ptr_factory_(this) {
   DCHECK(classic_discovery_manager_.get());
 }
 
 BluetoothAdapterMac::~BluetoothAdapterMac() {
 }
 
-void BluetoothAdapterMac::AddObserver(BluetoothAdapter::Observer* observer) {
-  DCHECK(observer);
-  observers_.AddObserver(observer);
-}
-
-void BluetoothAdapterMac::RemoveObserver(BluetoothAdapter::Observer* observer) {
-  DCHECK(observer);
-  observers_.RemoveObserver(observer);
-}
-
 std::string BluetoothAdapterMac::GetAddress() const {
   return address_;
 }
 
 std::string BluetoothAdapterMac::GetName() const {
   return name_;
 }
 
 void BluetoothAdapterMac::SetName(const std::string& name,
                                   const base::Closure& callback,
@@ skipping 278 matching lines @@
     DCHECK_EQ(num_removed, 1U);
   }
 
   // Add any new paired devices.
   for (IOBluetoothDevice* device in [IOBluetoothDevice pairedDevices]) {
     DeviceAdded(device);
   }
 }
 
 }  // namespace device