Remove DeviceMonitorLinux::WillDestroyCurrentMessageLoop().

device/hid/hid_service.cc

Index: device/hid/hid_service.cc
diff --git a/device/hid/hid_service.cc b/device/hid/hid_service.cc
index 1e118ef622a136115a7d046dd81a2484a8bceee9..cee3980b9dc86879258bf017b7a4fb304ec7efc4 100644
--- a/device/hid/hid_service.cc
+++ b/device/hid/hid_service.cc
@@ -49,6 +49,13 @@ std::unique_ptr<HidService> HidService::Create(
 #endif
 }
 
+void HidService::Shutdown() {
+#if DCHECK_IS_ON()
+  DCHECK(!did_shutdown_);
+  did_shutdown_ = true;
+#endif
+}
+
 void HidService::GetDevices(const GetDevicesCallback& callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (enumeration_ready_) {
@@ -82,11 +89,13 @@ scoped_refptr<HidDeviceInfo> HidService::GetDeviceInfo(
   return it->second;
 }
 
-HidService::HidService() : enumeration_ready_(false) {
-}
+HidService::HidService() = default;
 
 HidService::~HidService() {
   DCHECK(thread_checker_.CalledOnValidThread());
+#if DCHECK_IS_ON()
+  DCHECK(did_shutdown_);
+#endif
 }
 
 void HidService::AddDevice(scoped_refptr<HidDeviceInfo> device_info) {