Runtime checks so that CoreBluetooth only used on >= 10.10

device/bluetooth/bluetooth_low_energy_discovery_manager_mac.mm

 // Copyright 2015 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_low_energy_discovery_manager_mac.h"
 
 #include "base/mac/mac_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/sys_string_conversions.h"
 #include "device/bluetooth/bluetooth_low_energy_device_mac.h"
@@ skipping 61 matching lines @@
 
 - (void)centralManagerDidUpdateState:(CBCentralManager*)central {
   // Notifies when the powered state of the central manager changed.
   delegate_->TryStartDiscovery();
 }
 
 @end
 
 BluetoothLowEnergyDiscoveryManagerMac::
     ~BluetoothLowEnergyDiscoveryManagerMac() {
-  // Set the manager's delegate to nil since the object it points to
-  // (|bridge_|) will be deallocated while |manager_| is leaked.
-  if (base::mac::IsOSLionOrLater()) {
-    // CoreBluetooth only available in OSX 10.7 and later.
-    SEL selector = NSSelectorFromString(@"setDelegate:");
-    [manager_ performSelector:selector withObject:nil];
-  }
 }
 
 bool BluetoothLowEnergyDiscoveryManagerMac::IsDiscovering() const {
   return discovering_;
 }
 
 void BluetoothLowEnergyDiscoveryManagerMac::StartDiscovery(
     BluetoothDevice::UUIDList services_uuids) {
   discovering_ = true;
   pending_ = true;
@@ skipping 15 matching lines @@
     return;
   }
 
   // Converts the services UUIDs to a CoreBluetooth data structure.
   NSMutableArray* services = nil;
   if (!services_uuids_.empty()) {
     services = [NSMutableArray array];
     for (auto& service_uuid : services_uuids_) {
       NSString* uuidString =
           base::SysUTF8ToNSString(service_uuid.canonical_value().c_str());
-      Class aClass = NSClassFromString(@"CBUUID");
-      CBUUID* uuid = [aClass UUIDWithString:uuidString];
+      CBUUID* uuid = [CBUUID UUIDWithString:uuidString];
       [services addObject:uuid];
     }
   };
 
   [manager_ scanForPeripheralsWithServices:services options:nil];
   pending_ = false;
 }
 
 void BluetoothLowEnergyDiscoveryManagerMac::StopDiscovery() {
   if (discovering_ && !pending_) {
     [manager_ stopScan];
   }
   discovering_ = false;
 }
 
 void BluetoothLowEnergyDiscoveryManagerMac::DiscoveredPeripheral(
     CBPeripheral* peripheral,
     NSDictionary* advertisementData,
     int rssi) {
   observer_->LowEnergyDeviceUpdated(peripheral, advertisementData, rssi);
 }
 
 void BluetoothLowEnergyDiscoveryManagerMac::SetManagerForTesting(
     CBCentralManager* manager) {
-  // setDelegate is only available in OSX 10.7 and later.
-  CHECK(base::mac::IsOSLionOrLater());
-  SEL selector = NSSelectorFromString(@"setDelegate:");
-  [manager performSelector:selector withObject:bridge_];
+  // For stability we only use CoreBluetooth on OS X >= 10.10.
+  CHECK(base::mac::IsOSYosemiteOrLater());
+  [manager setDelegate:bridge_];
   manager_.reset(manager);
 }
 
 BluetoothLowEnergyDiscoveryManagerMac*
 BluetoothLowEnergyDiscoveryManagerMac::Create(Observer* observer) {
   return new BluetoothLowEnergyDiscoveryManagerMac(observer);
 }
 
 BluetoothLowEnergyDiscoveryManagerMac::BluetoothLowEnergyDiscoveryManagerMac(
     Observer* observer)
     : observer_(observer) {
+  // For stability we only use CoreBluetooth on OS X >= 10.10.  Thus
+  // BluetoothLowEnergyDiscoveryManagerMac should only be instantiated if on >=
+  // 10.10.
+  CHECK(base::mac::IsOSYosemiteOrLater());
   bridge_.reset([[BluetoothLowEnergyDiscoveryManagerMacBridge alloc]
       initWithManager:this]);
-  // Since CoreBluetooth is only available on OS X 10.7 or later, we
-  // instantiate CBCentralManager only for OS X >= 10.7.
-  if (base::mac::IsOSLionOrLater()) {
-    Class aClass = NSClassFromString(@"CBCentralManager");
-    manager_.reset(
-        [[aClass alloc] initWithDelegate:bridge_
-                                   queue:dispatch_get_main_queue()]);
-    // Increment reference count, see comment at declaration.
-    [manager_ retain];
-  }
+  manager_.reset(
+      [[CBCentralManager alloc] initWithDelegate:bridge_
+                                           queue:dispatch_get_main_queue()]);
   discovering_ = false;
 }