Refactor ozone drm cursor code for mojo

ui/ozone/platform/drm/mus_thread_proxy.cc

Index: ui/ozone/platform/drm/mus_thread_proxy.cc
diff --git a/ui/ozone/platform/drm/mus_thread_proxy.cc b/ui/ozone/platform/drm/mus_thread_proxy.cc
index 795b084cf4b2a7ff654d877407f9354f9f1602af..a331c522a10a97d5831d3c895ae2e5a024584a73 100644
--- a/ui/ozone/platform/drm/mus_thread_proxy.cc
+++ b/ui/ozone/platform/drm/mus_thread_proxy.cc
@@ -20,6 +20,8 @@ MusThreadProxy::MusThreadProxy()
       drm_thread_(nullptr),
       weak_ptr_factory_(this) {}
 
+void MusThreadProxy::InitializeOnEvdev() {}
+
 MusThreadProxy::~MusThreadProxy() {
   DCHECK(on_window_server_thread_.CalledOnValidThread());
   FOR_EACH_OBSERVER(GpuThreadObserver, gpu_thread_observers_,