Make ozone/drm/mojo more immune to startup races

ui/ozone/platform/drm/cursor_proxy_mojo.cc

Index: ui/ozone/platform/drm/cursor_proxy_mojo.cc
diff --git a/ui/ozone/platform/drm/cursor_proxy_mojo.cc b/ui/ozone/platform/drm/cursor_proxy_mojo.cc
index a0918fc0a2250a92eb8a51560bd2af26a22277b5..3e91f1b7ed2c962031c5cb1a26d5ebb826d04f83 100644
--- a/ui/ozone/platform/drm/cursor_proxy_mojo.cc
+++ b/ui/ozone/platform/drm/cursor_proxy_mojo.cc
@@ -25,6 +25,8 @@ void CursorProxyMojo::CursorSet(gfx::AcceleratedWidget widget,
                                 const std::vector<SkBitmap>& bitmaps,
                                 const gfx::Point& location,
                                 int frame_delay_ms) {
+  if (!have_gpu_thread_)
+    return;
   if (evdev_ref_ == base::PlatformThread::CurrentRef()) {
     evdev_cursor_ptr_->SetCursor(widget, bitmaps, location, frame_delay_ms);
   } else {
@@ -34,6 +36,8 @@ void CursorProxyMojo::CursorSet(gfx::AcceleratedWidget widget,
 
 void CursorProxyMojo::Move(gfx::AcceleratedWidget widget,
                            const gfx::Point& location) {
+  if (!have_gpu_thread_)
+    return;
   if (evdev_ref_ == base::PlatformThread::CurrentRef()) {
     evdev_cursor_ptr_->MoveCursor(widget, location);
   } else {
@@ -41,4 +45,14 @@ void CursorProxyMojo::Move(gfx::AcceleratedWidget widget,
   }
 }
 
+void CursorProxyMojo::OnGpuProcessLaunched() {}
+
+void CursorProxyMojo::OnGpuThreadReady() {
+  have_gpu_thread_ = true;
+}
+
+void CursorProxyMojo::OnGpuThreadRetired() {
+  have_gpu_thread_ = false;
+}
+
 }  // namespace ui