Runtime checks so that CoreBluetooth only used on >= 10.10

device/bluetooth/bluetooth_adapter_mac_unittest.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 "base/mac/mac_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/test/test_simple_task_runner.h"
 #include "device/bluetooth/bluetooth_adapter.h"
 #include "device/bluetooth/bluetooth_adapter_mac.h"
 #include "device/bluetooth/bluetooth_discovery_session.h"
 #include "device/bluetooth/test/mock_bluetooth_central_manager_mac.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace device {
 
 class BluetoothAdapterMacTest : public testing::Test {
  public:
   BluetoothAdapterMacTest()
       : ui_task_runner_(new base::TestSimpleTaskRunner()),
         adapter_(new BluetoothAdapterMac()),
         adapter_mac_(static_cast<BluetoothAdapterMac*>(adapter_.get())),
         callback_count_(0),
         error_callback_count_(0) {
     adapter_mac_->InitForTest(ui_task_runner_);
   }
 
   // Helper methods for setup and access to BluetoothAdapterMacTest's members.
   bool SetMockCentralManager() {
-    Class aClass = NSClassFromString(@"CBCentralManager");
-    if (aClass == nil) {
-      LOG(WARNING) << "CoreBluetooth not available, skipping unit test.";
+    if (!base::mac::IsOSYosemiteOrLater()) {
+      // For stability we only use CoreBluetooth on OS X >= 10.10.  Thus on
+      // previous OS X versions the code cannot be tested.
+      LOG(WARNING) << "OS X version < 10.10, skipping unit test.";
       return false;
     }
     mock_central_manager_ = [[MockCentralManager alloc] init];
     adapter_mac_->low_energy_discovery_manager_->SetManagerForTesting(
         mock_central_manager_);
     return true;
   }
 
   void AddDiscoverySession(BluetoothDiscoveryFilter* discovery_filter) {
     adapter_mac_->AddDiscoverySession(
@@ skipping 113 matching lines @@
   RemoveDiscoverySession(discovery_filter.get());
   EXPECT_EQ(0, callback_count_);
   EXPECT_EQ(1, error_callback_count_);
   EXPECT_EQ(0, NumDiscoverySessions());
 
   // Check that stopScan was not called.
   EXPECT_EQ(0, [mock_central_manager_ stopScanCallCount]);
 }
 
 }  // namespace device