Migrate GpuChildThread to use ConnectionFilter instead of the ChildThread's InterfaceRegistry to exp

content/gpu/gpu_child_thread.h

Index: content/gpu/gpu_child_thread.h
diff --git a/content/gpu/gpu_child_thread.h b/content/gpu/gpu_child_thread.h
index a0e2bd36d52727e375831d86085c21217f206fcf..221c48076de8afc8f596a1ea5052114ef1aad92e 100644
--- a/content/gpu/gpu_child_thread.h
+++ b/content/gpu/gpu_child_thread.h
@@ -15,6 +15,7 @@
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
@@ -72,6 +73,8 @@ class GpuChildThread : public ChildThreadImpl,
   void Init(const base::Time& process_start_time);
 
  private:
+  class QueueingConnectionFilter;
+
   GpuChildThread(const ChildThreadImpl::Options& options,
                  std::unique_ptr<gpu::GpuWatchdogThread> gpu_watchdog_thread,
                  bool dead_on_arrival,
@@ -130,6 +133,8 @@ class GpuChildThread : public ChildThreadImpl,
   std::unique_ptr<ui::GpuService> gpu_service_;
   mojo::AssociatedBinding<ui::mojom::GpuMain> gpu_main_binding_;
 
+  base::WeakPtr<QueueingConnectionFilter> queueing_filter_;
+
   DISALLOW_COPY_AND_ASSIGN(GpuChildThread);
 };