Revert of Deletes mojo::Callback

components/arc/bluetooth/arc_bluetooth_bridge.cc

 // Copyright 2016 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 "components/arc/bluetooth/arc_bluetooth_bridge.h"
 
 #include <fcntl.h>
 #include <stddef.h>
 
 #include <iomanip>
@@ skipping 371 matching lines @@
     return;
   }
 
   discovery_session_->Stop(base::Bind(&ArcBluetoothBridge::OnDiscoveryStopped,
                                       weak_factory_.GetWeakPtr()),
                            base::Bind(&ArcBluetoothBridge::OnDiscoveryError,
                                       weak_factory_.GetWeakPtr()));
 }
 
 void ArcBluetoothBridge::OnPoweredOn(
-    const base::Callback<void(mojom::BluetoothAdapterState)>& callback) const {
+    const mojo::Callback<void(mojom::BluetoothAdapterState)>& callback) const {
   callback.Run(mojom::BluetoothAdapterState::ON);
   SendCachedPairedDevices();
 }
 
 void ArcBluetoothBridge::OnPoweredOff(
-    const base::Callback<void(mojom::BluetoothAdapterState)>& callback) const {
+    const mojo::Callback<void(mojom::BluetoothAdapterState)>& callback) const {
   callback.Run(mojom::BluetoothAdapterState::OFF);
 }
 
 void ArcBluetoothBridge::OnPoweredError(
-    const base::Callback<void(mojom::BluetoothAdapterState)>& callback) const {
+    const mojo::Callback<void(mojom::BluetoothAdapterState)>& callback) const {
   LOG(WARNING) << "failed to change power state";
 
   callback.Run(bluetooth_adapter_->IsPowered()
                    ? mojom::BluetoothAdapterState::ON
                    : mojom::BluetoothAdapterState::OFF);
 }
 
 void ArcBluetoothBridge::OnDiscoveryStarted(
     std::unique_ptr<BluetoothDiscoverySession> session) {
   if (!HasBluetoothInstance())
@@ skipping 897 matching lines @@
     // to
     // make sure the bond state machine on Android is ready to take the
     // pair-done event. Otherwise the pair-done event will be dropped as an
     // invalid change of paired status.
     OnPairing(addr->Clone());
     OnPairedDone(std::move(addr));
   }
 }
 
 }  // namespace arc