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..f3c6720649a00d0ae765a6c4de55df4760539057 100644
--- a/services/ui/gpu/gpu_service.h
+++ b/services/ui/gpu/gpu_service.h
@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/task/cancelable_task_tracker.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/threading/thread.h"
 #include "build/build_config.h"
@@ -78,6 +79,8 @@ class GpuService : public gpu::GpuChannelManagerDelegate,
  private:
   friend class GpuMain;
 
+  void BindGpuHostOnIO(mojom::GpuHostPtrInfo ptr_info);
+
   gpu::SyncPointManager* sync_point_manager() { return sync_point_manager_; }
 
   gpu::gles2::MailboxManager* mailbox_manager() {
@@ -155,7 +158,7 @@ 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_;
 
@@ -165,6 +168,7 @@ class GpuService : public gpu::GpuChannelManagerDelegate,
   gpu::SyncPointManager* sync_point_manager_ = nullptr;
 
   mojo::BindingSet<mojom::GpuService> bindings_;
+  base::CancelableTaskTracker task_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuService);
 };