mus-gpu: Talk to the GpuHost from the IO thread.

services/ui/gpu/gpu_service.h

Index: services/ui/gpu/gpu_service.h
diff --git a/services/ui/gpu/gpu_service.h b/services/ui/gpu/gpu_service.h
index 3ad7b5e60d4d6c2e194fb091faf7547e5b902d04..9faf51350aeb93401de147f8bf8d0db7c376d145 100644
--- a/services/ui/gpu/gpu_service.h
+++ b/services/ui/gpu/gpu_service.h
@@ -155,7 +155,7 @@ class GpuService : public gpu::GpuChannelManagerDelegate,
   // Information about general chrome feature support for the GPU.
   gpu::GpuFeatureInfo gpu_feature_info_;
 
-  mojom::GpuHostPtr gpu_host_;
+  scoped_refptr<mojom::ThreadSafeGpuHostPtr> gpu_host_;
   std::unique_ptr<gpu::GpuChannelManager> gpu_channel_manager_;
   std::unique_ptr<media::MediaGpuChannelManager> media_gpu_channel_manager_;