Remove DeviceMonitorLinux::WillDestroyCurrentMessageLoop().

device/test/test_device_client.cc

Index: device/test/test_device_client.cc
diff --git a/device/test/test_device_client.cc b/device/test/test_device_client.cc
index 7a6c0526fb63b1d89802f8d539571d6279e3a238..8ee7f52ad24f2f8d6302f27014bbb47e9f2bce57 100644
--- a/device/test/test_device_client.cc
+++ b/device/test/test_device_client.cc
@@ -19,7 +19,12 @@ TestDeviceClient::TestDeviceClient(
     scoped_refptr<base::SingleThreadTaskRunner> blocking_task_runner)
     : blocking_task_runner_(blocking_task_runner) {}
 
-TestDeviceClient::~TestDeviceClient() {}
+TestDeviceClient::~TestDeviceClient() {
+  if (hid_service_)
+    hid_service_->Shutdown();
+  if (usb_service_)
+    usb_service_->Shutdown();
+}
 
 HidService* TestDeviceClient::GetHidService() {
 #if !defined(OS_ANDROID) && !defined(OS_IOS) && \