Replace deprecated base::NonThreadSafe in media/gpu in favor of SequenceChecker.

media/gpu/ipc/client/gpu_video_encode_accelerator_host.h

Index: media/gpu/ipc/client/gpu_video_encode_accelerator_host.h
diff --git a/media/gpu/ipc/client/gpu_video_encode_accelerator_host.h b/media/gpu/ipc/client/gpu_video_encode_accelerator_host.h
index acf95724390bdfd6a0b3af9e0f6516482fb570b1..9e5d48ac9a7830031cabc915da681bc8f073f0e2 100644
--- a/media/gpu/ipc/client/gpu_video_encode_accelerator_host.h
+++ b/media/gpu/ipc/client/gpu_video_encode_accelerator_host.h
@@ -13,8 +13,8 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/sequence_checker.h"
 #include "base/single_thread_task_runner.h"
-#include "base/threading/non_thread_safe.h"
 #include "gpu/config/gpu_info.h"
 #include "gpu/ipc/client/command_buffer_proxy_impl.h"
 #include "ipc/ipc_listener.h"
@@ -43,8 +43,7 @@ namespace media {
 class GpuVideoEncodeAcceleratorHost
     : public IPC::Listener,
       public VideoEncodeAccelerator,
-      public gpu::CommandBufferProxyImpl::DeletionObserver,
-      public base::NonThreadSafe {
+      public gpu::CommandBufferProxyImpl::DeletionObserver {
  public:
   // |this| is guaranteed not to outlive |impl|.  (See comments for |impl_|.)
   explicit GpuVideoEncodeAcceleratorHost(gpu::CommandBufferProxyImpl* impl);
@@ -126,6 +125,8 @@ class GpuVideoEncodeAcceleratorHost
   // constructed.
   scoped_refptr<base::SingleThreadTaskRunner> media_task_runner_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   // WeakPtr factory for posting tasks back to itself.
   base::WeakPtrFactory<GpuVideoEncodeAcceleratorHost> weak_this_factory_;