Deprecate NonThreadSafe in remoting in favor of SequenceChecker.

remoting/protocol/pseudotcp_adapter.h

Index: remoting/protocol/pseudotcp_adapter.h
diff --git a/remoting/protocol/pseudotcp_adapter.h b/remoting/protocol/pseudotcp_adapter.h
index bde7ccab45f074c1c10df5180ab591a3e2d63853..93e1ac7dd29ad652cadd70a9eb5c866571a8193a 100644
--- a/remoting/protocol/pseudotcp_adapter.h
+++ b/remoting/protocol/pseudotcp_adapter.h
@@ -12,7 +12,7 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "net/log/net_log_with_source.h"
 #include "remoting/protocol/p2p_stream_socket.h"
 #include "third_party/webrtc/p2p/base/pseudotcp.h"
@@ -27,7 +27,7 @@ class P2PDatagramSocket;
 // while PseudoTcp cannot, the core of the PseudoTcpAdapter is reference
 // counted, with a reference held by the adapter, and an additional reference
 // held on the stack during callbacks.
-class PseudoTcpAdapter : public P2PStreamSocket, base::NonThreadSafe {
+class PseudoTcpAdapter : public P2PStreamSocket {
  public:
   explicit PseudoTcpAdapter(std::unique_ptr<P2PDatagramSocket> socket);
   ~PseudoTcpAdapter() override;
@@ -75,6 +75,8 @@ class PseudoTcpAdapter : public P2PStreamSocket, base::NonThreadSafe {
 
   net::NetLogWithSource net_log_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(PseudoTcpAdapter);
 };