Bluetooth: macOS: DidModifyServices can happens while scanning

device/bluetooth/test/mock_bluetooth_cbcharacteristic_mac.mm

 // 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 "device/bluetooth/test/mock_bluetooth_cbcharacteristic_mac.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_nsobject.h"
 #include "device/bluetooth/bluetooth_gatt_characteristic.h"
 #include "device/bluetooth/test/mock_bluetooth_cbdescriptor_mac.h"
@@ skipping 76 matching lines @@
   return result;
 }
 }  // namespace
 }  // device
 
 @interface MockCBCharacteristic () {
   // Owner of this instance.
   CBService* _service;
   scoped_nsobject<CBUUID> _UUID;
   CBCharacteristicProperties _cb_properties;
-  scoped_nsobject<NSMutableArray> _simulatedDescriptors;
-  scoped_nsobject<NSArray> _descriptors;
+  scoped_nsobject<NSMutableArray> _descriptors;
   scoped_nsobject<NSObject> _value;
   BOOL _notifying;
 }
 @end
 
 @implementation MockCBCharacteristic
 
 - (instancetype)initWithService:(CBService*)service
                          CBUUID:(CBUUID*)uuid
                      properties:(int)properties {
   self = [super init];
   if (self) {
     _service = service;
     _UUID.reset([uuid retain]);
     _cb_properties =
         device::GattCharacteristicPropertyToCBCharacteristicProperty(
             properties);
-    _simulatedDescriptors.reset([[NSMutableArray alloc] init]);
+    _descriptors.reset([[NSMutableArray alloc] init]);
   }
   return self;
 }
 
 - (BOOL)isKindOfClass:(Class)aClass {
   if (aClass == [CBCharacteristic class] ||
       [aClass isSubclassOfClass:[CBCharacteristic class]]) {
     return YES;
   }
   return [super isKindOfClass:aClass];
@@ skipping 55 matching lines @@
 }
 
 - (void)simulateGattCharacteristicChangedWithValue:(NSData*)value {
   _value.reset([value copy]);
   CBPeripheral* peripheral = _service.peripheral;
   [peripheral.delegate peripheral:peripheral
       didUpdateValueForCharacteristic:self.characteristic
                                 error:nil];
 }
 
-- (void)simulateDescriptorWithUUID:(CBUUID*)uuid {
+- (void)addDescriptorWithUUID:(CBUUID*)uuid {
   scoped_nsobject<MockCBDescriptor> descriptor_mock([[MockCBDescriptor alloc]
       initWithCharacteristic:self.characteristic
                       CBUUID:uuid]);
-  [_simulatedDescriptors.get() addObject:descriptor_mock];
-}
-
-- (void)discoverDescriptors {
-  _descriptors.reset([_simulatedDescriptors copy]);
+  [_descriptors.get() addObject:descriptor_mock];
 }
 
 - (CBUUID*)UUID {
   return _UUID.get();
 }
 
 - (CBCharacteristic*)characteristic {
   return ObjCCast<CBCharacteristic>(self);
 }
 
@@ skipping 11 matching lines @@
 
 - (id)value {
   return _value.get();
 }
 
 - (BOOL)isNotifying {
   return _notifying;
 }
 
 @end