Deprecate NonThreadSafe in remoting in favor of SequenceChecker.

remoting/host/native_messaging/pipe_messaging_channel.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef REMOTING_HOST_NATIVE_MESSAGING_PIPE_MESSAGING_CHANNEL_H_
 #define REMOTING_HOST_NATIVE_MESSAGING_PIPE_MESSAGING_CHANNEL_H_
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/files/file.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "extensions/browser/api/messaging/native_messaging_channel.h"
 #include "remoting/host/native_messaging/native_messaging_reader.h"
 #include "remoting/host/native_messaging/native_messaging_writer.h"
 
 namespace base {
 class Value;
 }  // namespace base
 
 namespace remoting {
 
 // An implementation of extensions::NativeMessagingChannel using a pipe. It
 // is used by the It2MeNativeMessagingHost and Me2MeNativeMessagingHost to
 // communicate with the chrome process.
 // TODO(kelvinp): Move this class to the extensions/browser/api/messaging
 // directory.
-class PipeMessagingChannel : public extensions::NativeMessagingChannel,
-                             public base::NonThreadSafe {
+class PipeMessagingChannel : public extensions::NativeMessagingChannel {
  public:
   typedef extensions::NativeMessagingChannel::EventHandler EventHandler;
 
   // Constructs an object taking the ownership of |input| and |output|. Closes
   // |input| and |output| to prevent the caller from using them.
   PipeMessagingChannel(base::File input, base::File output);
   ~PipeMessagingChannel() override;
 
   // extensions::NativeMessagingChannel implementation.
   void Start(EventHandler* event_handler) override;
   void SendMessage(std::unique_ptr<base::Value> message) override;
 
  private:
   // Processes a message received from the client app.
   void ProcessMessage(std::unique_ptr<base::Value> message);
 
   // Initiates shutdown.
   void Shutdown();
 
   NativeMessagingReader native_messaging_reader_;
   std::unique_ptr<NativeMessagingWriter> native_messaging_writer_;
 
   EventHandler* event_handler_;
   base::WeakPtr<PipeMessagingChannel> weak_ptr_;
+
+  SEQUENCE_CHECKER(sequence_checker_);
+
   base::WeakPtrFactory<PipeMessagingChannel> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PipeMessagingChannel);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_NATIVE_MESSAGING_PIPE_MESSAGING_CHANNEL_H_